From nek5000-users at lists.mcs.anl.gov Wed Aug 1 00:01:15 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Wed, 1 Aug 2018 05:01:15 +0000 Subject: [Nek5000-users] Impose velocity BC on the wall Message-ID: Dear Nek users, I am trying to impose a periodic velocity to simulation blowing and suction on a flat plate. The current inlet has a specified velocity whereas the top and outlet are specified as 'O'. The bottom is wall, 'W'. Does anyone has any experience of specifing a temporally periodic velocity on a narrow strip of the wall? I tried to define this velocity in the usrchk like, do i = 1, n x = xm1(...) y = ym1(...) IF (y .eq. 0) then if(x.LT... .and. x.GT...) then vy (...)= ... endif ENDIF enddo But this does not work. Could anyone give me some suggestions please? Thanks in advance -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Wed Aug 1 02:42:36 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Wed, 1 Aug 2018 09:42:36 +0200 Subject: [Nek5000-users] Impose velocity BC on the wall In-Reply-To: References: Message-ID: An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Wed Aug 1 03:48:05 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Wed, 1 Aug 2018 08:48:05 +0000 Subject: [Nek5000-users] Impose velocity BC on the wall In-Reply-To: References: , Message-ID: Yes - ... If you simply define the region(s) of interest with 'v ' for your BC, then you can simply user userbc. For example omega = 3 ux=0 uy=sin(omega*time) uz=0 would be one such function. Paul ________________________________ From: Nek5000-users on behalf of nek5000-users at lists.mcs.anl.gov Sent: Wednesday, August 1, 2018 2:42:36 AM To: nek5000-users at lists.mcs.anl.gov Subject: Re: [Nek5000-users] Impose velocity BC on the wall Hi, if I am not mistaken, 'W' will always impose zero velocity. You may want to use 'v' instead. If you set zero velocity, it will behave like a wall. In addition, there are several things you should change: 1) you should do this in the userbc subroutine that is called once for each point on the boundary where it needs a value (so you don't have to write the loop yourself). 2) there you need to set the variables ux, uy, uz instead of vx, vy, vz. Probably similar to what you do for inflow. 3) be careful checking equalities with floating point numbers, in some cases you could have y very small but non zero. Guillaume Le 01/08/2018 ? 07:01, nek5000-users at lists.mcs.anl.gov a ?crit : Dear Nek users, I am trying to impose a periodic velocity to simulation blowing and suction on a flat plate. The current inlet has a specified velocity whereas the top and outlet are specified as 'O'. The bottom is wall, 'W'. Does anyone has any experience of specifing a temporally periodic velocity on a narrow strip of the wall? I tried to define this velocity in the usrchk like, do i = 1, n x = xm1(...) y = ym1(...) IF (y .eq. 0) then if(x.LT... .and. x.GT...) then vy (...)= ... endif ENDIF enddo But this does not work. Could anyone give me some suggestions please? Thanks in advance _______________________________________________ Nek5000-users mailing list Nek5000-users at lists.mcs.anl.gov https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Wed Aug 1 10:16:37 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Wed, 1 Aug 2018 15:16:37 +0000 Subject: [Nek5000-users] Restart using rea Message-ID: Dear Nek users, I ran into a problem when restarting using the .rea file. In the .rea file, I specified the name of the file (the file was renamed from the last time step of the previous simuiatlion)to restart with: ***** NO THERMAL BOUNDARY CONDITIONS ***** 1 PRESOLVE/RESTART OPTIONS ***** restart.fld Without changing the time step size, I restarted the simulation, but I received an error: Step 581, time= 3.0955000E+02, DT= 5.0000000E-02, C= 4.240 4.3486E+01 1.1724E-01 Solving for fluid 581 Hmholtz VELX 12 1.5661E-12 7.4073E-01 5.0000E-12 581 Hmholtz VELY 11 9.6329E-13 3.3660E+00 5.0000E-12 581 Project PRES 5.5975E-05 1.6744E+00 2.9913E+04 13 20 581 U-PRES gmres 120 6.1973E-10 1.8658E-06 5.0000E-12 4.3239E-02 1.0688E-01 581 Fluid done 3.0955E+02 1.1453E-01 581 3.09550E+02 6.46747E+01 0.00000E+00 7.53982E+02 blasius: delta* CFL, Ctarg! 7.39542251238818 0.500000000000000 The original CFL was only 0.028 or so, after restart, it fluctuates significantly and eventually it quits for CFL being too large. Could anyone help me on this please? Many thanks -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Wed Aug 1 10:43:16 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Wed, 1 Aug 2018 15:43:16 +0000 Subject: [Nek5000-users] Restart using rea In-Reply-To: References: Message-ID: The usual first step here is to restart with a lower value of dt. In this case, I would recommend reducing dt by about a factor of 5 or 10 and seeing if this survives with a reasonable Courant number. hth, Paul ________________________________ From: Nek5000-users on behalf of nek5000-users at lists.mcs.anl.gov Sent: Wednesday, August 1, 2018 10:16:37 AM To: nek5000-users at lists.mcs.anl.gov Subject: [Nek5000-users] Restart using rea Dear Nek users, I ran into a problem when restarting using the .rea file. In the .rea file, I specified the name of the file (the file was renamed from the last time step of the previous simuiatlion)to restart with: ***** NO THERMAL BOUNDARY CONDITIONS ***** 1 PRESOLVE/RESTART OPTIONS ***** restart.fld Without changing the time step size, I restarted the simulation, but I received an error: Step 581, time= 3.0955000E+02, DT= 5.0000000E-02, C= 4.240 4.3486E+01 1.1724E-01 Solving for fluid 581 Hmholtz VELX 12 1.5661E-12 7.4073E-01 5.0000E-12 581 Hmholtz VELY 11 9.6329E-13 3.3660E+00 5.0000E-12 581 Project PRES 5.5975E-05 1.6744E+00 2.9913E+04 13 20 581 U-PRES gmres 120 6.1973E-10 1.8658E-06 5.0000E-12 4.3239E-02 1.0688E-01 581 Fluid done 3.0955E+02 1.1453E-01 581 3.09550E+02 6.46747E+01 0.00000E+00 7.53982E+02 blasius: delta* CFL, Ctarg! 7.39542251238818 0.500000000000000 The original CFL was only 0.028 or so, after restart, it fluctuates significantly and eventually it quits for CFL being too large. Could anyone help me on this please? Many thanks -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Wed Aug 1 11:34:25 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Wed, 1 Aug 2018 16:34:25 +0000 Subject: [Nek5000-users] Pipe Roughness Message-ID: Yes, that helps. Thank you so much Mr.George. Now, it is working, and I have attached the script just in case for everyone who wants to use it on Cray system. Ali Embry-Riddle Aeronautical University -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: neknekpbs Type: application/octet-stream Size: 838 bytes Desc: neknekpbs URL: From nek5000-users at lists.mcs.anl.gov Thu Aug 2 05:58:57 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Thu, 2 Aug 2018 16:28:57 +0530 Subject: [Nek5000-users] Parabolic velocity profile at channel inlet boundary Message-ID: Hi Nek users, I am trying to simulate expansion channel case in the laminar region. For the fully developed flow, the velocity profile should be parabolic at the inlet boundary. I am not able to provide Parabolic inlet profile at the inlet. Could anyone help me with this please? Thanks in advance Alok Mishra -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Thu Aug 2 07:59:37 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Thu, 2 Aug 2018 12:59:37 +0000 Subject: [Nek5000-users] Parabolic velocity profile at channel inlet boundary In-Reply-To: References: Message-ID: Hi Alok, Assuming your inlet ranges from y = y0 to y1 and your flow is in the x direction, the following should work in userbc: y0 = y1 = const = ux = const*(y-y0)*(y1-y) uy=0 uz=0 where const is some number you choose. You have to supply const, y0, and y1. Also, you must have 'v ' boundary conditions on the inlet faces of the elements that are at the inlet. hth Paul ________________________________ From: Nek5000-users on behalf of nek5000-users at lists.mcs.anl.gov Sent: Thursday, August 2, 2018 5:58:57 AM To: nek5000-users at lists.mcs.anl.gov Subject: [Nek5000-users] Parabolic velocity profile at channel inlet boundary Hi Nek users, I am trying to simulate expansion channel case in the laminar region. For the fully developed flow, the velocity profile should be parabolic at the inlet boundary. I am not able to provide Parabolic inlet profile at the inlet. Could anyone help me with this please? Thanks in advance Alok Mishra -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Thu Aug 2 14:16:35 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Thu, 2 Aug 2018 14:16:35 -0500 Subject: [Nek5000-users] Makenek supported compiler error Message-ID: Hello, I am trying to run the eddy_uv the example in the quickstart guide:( http://nek5000.github.io/NekDoc/quickstart.html#visualization). I have gfortran installed, but for some reason, executing "makenek eddy_uv" results in the following error: "Cannot find a supported compiler!" Can you please tell me what is causing this? Thanks -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Fri Aug 3 00:05:25 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Fri, 03 Aug 2018 08:05:25 +0300 Subject: [Nek5000-users] =?utf-8?q?Interpolation_with_gfldr?= Message-ID: Hi, Neks! I am working with a complex geometry?which was built in gambit.?I have a velocity fields for my grid.?But I want to interpolate these velocity fields to a new grid. The old grid was changed without moving the geometry parameters, I just changed the position of the?computational nodes and reduced their number (see pictures old_grid and new_grid *).?During interpolation with?gfldr: ... call userchk call gfldr wing0.f00001 WARNING: Unable to find all mesh points in source fld 39404 done :: gfldr 0.20E+03 sec done :: userchk ... After that, interpolation ends as usual. The velocity field is interpolated perfectly, but the pressure field is not interpolated correctly? (see pictures pressure_field_before_interpolation and? pressure_field_after_interpolation ** ) . Tell me, what is my mistake? Is it possible to interpolate from a larger number of nodes to a smaller number of nodes? * https://drive.google.com/open?id=1DmsGxc_WR3_aJW0UpLHkcxAVzt5BzABK ? https://drive.google.com/open?id=1RbSsODF49DqGmyHnpz0Bktp-HDjW7j0w ? ** https://drive.google.com/open?id=16Ueepa1lo_aHjya3BnLn8fHI3ek0kvo8 ? ? ? https://drive.google.com/open?id=1CNiN8MdE7tNeu8T4jBtZBtMSX5dlXzNM Best regards, Elizabeth -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Sat Aug 4 08:21:44 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Sat, 4 Aug 2018 15:21:44 +0200 Subject: [Nek5000-users] Interpolation with gfldr In-Reply-To: References: Message-ID: Is your input file SP oder DP? Are you using Pn/Pn or Pn/Pn-2? On 4 Aug 2018, at 03:37, "nek5000-users at lists.mcs.anl.gov " > wrote: Hi, Neks! I am working with a complex geometry?which was built in gambit.?I have a velocity fields for my grid.?But I want to interpolate these velocity fields to a new grid. The old grid was changed without moving the geometry parameters, I just changed the position of the?computational nodes and reduced their number (see pictures old_grid and new_grid *).?During interpolation with?gfldr: ... call userchk call gfldr wing0.f00001 WARNING: Unable to find all mesh points in source fld 39404 done :: gfldr 0.20E+03 sec done :: userchk ... After that, interpolation ends as usual. The velocity field is interpolated perfectly, but the pressure field is not interpolated correctly?(see pictures pressure_field_before_interpolation and?pressure_field_after_interpolation **). Tell me, what is my mistake? Is it possible to interpolate from a larger number of nodes to a smaller number of nodes? *https://drive.google.com/open?id=1DmsGxc_WR3_aJW0UpLHkcxAVzt5BzABK ?https://drive.google.com/open?id=1RbSsODF49DqGmyHnpz0Bktp-HDjW7j0w? **https://drive.google.com/open?id=16Ueepa1lo_aHjya3BnLn8fHI3ek0kvo8? ? ?https://drive.google.com/open?id=1CNiN8MdE7tNeu8T4jBtZBtMSX5dlXzNM Best regards, Elizabeth _______________________________________________ Nek5000-users mailing list Nek5000-users at lists.mcs.anl.gov https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Fri Aug 10 14:09:09 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Fri, 10 Aug 2018 15:09:09 -0400 Subject: [Nek5000-users] Average Nusselt over a wall Message-ID: Hi Neks, I'm running some differentially heated cavity simulations and want to output the average Nusselt over a wall on each output timestep. Right now I'm calculating the temperature gradient like this: common /grad_t/ dTx(lt), dTy(lt), dTz(lt) parameter (lt=lx1*ly1*lz1*lelv) if(mod(istep,iostep).eq.0) then call gradm1(dTx,dTy,dTz,t) call dsavg(dTx) call dsavg(dTy) call dsavg(dTz) call outpost(dTx,dTy,dTz,pr,t,'grd') endif I would appreciate any suggestion to implement a way to calculate and dump the average Nusselt (-dT/dy) between dumps at each iostep time. Part of the motivation is save disk space by avoiding the call outpost of each field and then post processing the data. Regards, *Nicol?s* -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Fri Aug 10 14:42:40 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Fri, 10 Aug 2018 15:42:40 -0400 Subject: [Nek5000-users] Calculate Velocity Fluctuation Fields Message-ID: Hi Neks, I have read many entries in the archives regarding the way to calculate instantaneous fluctuations in velocity field, but I'm still unsure of the last steps to archive this. I understand that this is the workflow: 1) Running a case and call avg_all in usrchk() to get avg (), rms () and rm2 () files. 2) Create a file with .list extension to load in post-processing mode these results with this format: ------------------------- avg***0.f00001 avg***0.f00002 . . . avg***0.f****** ------------------------- 3) Set NSTEPS = 0 to enable post-processing mode. 4) Load in usrchk() the avg_all files with 'load_fld'. 5) Calculate u_i' = u_i - 6) Output the fluctuation fields call outpost(vx',vy',vz',pr,t,'***') How should I perform the 4th and 5th steps? Best regards, *Nicol?s* -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Mon Aug 13 11:16:37 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Mon, 13 Aug 2018 16:16:37 +0000 Subject: [Nek5000-users] Freestream BC Message-ID: Dear Nek users, I am wondering if freestream BC is available in the NEK5000? Coz I would like to run the Falkner-Skan BL using the Nek. I notice two convective BCs are ready to use, ?O? and ?ON?. But I do not think they are appropriate for the FSBL. Thanks for your help in advance -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Tue Aug 14 00:38:41 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Tue, 14 Aug 2018 07:38:41 +0200 Subject: [Nek5000-users] Freestream BC In-Reply-To: References: Message-ID: Hi, we have done FSC boundary layers in Nek5000, see the JFM paper: https://doi.org/10.1017/jfm.2017.466 On p833 we describe how we imposed the boundary conditions. I hope this helps. Philipp On 2018-08-13 18:16, nek5000-users at lists.mcs.anl.gov wrote: > Dear Nek users, > > I am wondering if freestream BC is available in the NEK5000? Coz I would > like to run the Falkner-Skan BL using the Nek. I notice two convective > BCs are ready to use, ?O? and ?ON?. But I do not think they are > appropriate for the FSBL. > > Thanks for your help in advance > > > > _______________________________________________ > Nek5000-users mailing list > Nek5000-users at lists.mcs.anl.gov > https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users > From nek5000-users at lists.mcs.anl.gov Wed Aug 15 04:16:15 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Wed, 15 Aug 2018 09:16:15 +0000 Subject: [Nek5000-users] reshape array Message-ID: Hi all, All average streamwise velocity are stored in this array "common /avg/ uavg(lx1,ly1,lz1,lelv)" but I want this array to be reshaped into "common /abcd/ abcd(lx1*ly1*lz1,lelv)" The following didn't work: common /avg/ uavg(lx1,ly1,lz1,lelv) common /abcd/ abcd(lx1*ly1*lz1,lelv) abcd=reshape(uavg,(/ lx1*ly1*lz1,lelv /)) This is how array reshaping works in fortran. Unfortunately, didn't work in nek. Anyone knows why? Many thanks in advance for your replies. -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Wed Aug 15 04:25:30 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Wed, 15 Aug 2018 11:25:30 +0200 Subject: [Nek5000-users] reshape array In-Reply-To: References: Message-ID: You don't need to do that. Just use the desired "shape" in your subroutine. On August 15, 2018 11:16:15 AM GMT+02:00, nek5000-users at lists.mcs.anl.gov wrote: >Hi all, > >All average streamwise velocity are stored in this array > >"common /avg/ uavg(lx1,ly1,lz1,lelv)" > >but I want this array to be reshaped into > >"common /abcd/ abcd(lx1*ly1*lz1,lelv)" > >The following didn't work: > > >common /avg/ uavg(lx1,ly1,lz1,lelv) >common /abcd/ abcd(lx1*ly1*lz1,lelv) > > >abcd=reshape(uavg,(/ lx1*ly1*lz1,lelv /)) > > >This is how array reshaping works in fortran. Unfortunately, didn't >work in nek. Anyone knows why? > >Many thanks in advance for your replies. -- Sent from my Android device with K-9 Mail. Please excuse my brevity. -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Wed Aug 15 09:34:29 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Wed, 15 Aug 2018 14:34:29 +0000 Subject: [Nek5000-users] reshape array In-Reply-To: References: Message-ID: f77 array declarations do either one or two things, depending on whether the array is passed as an argument or is declared within the scope of the routine or function in question. If the array is in a common block or is declared for the first time within a subroutine/function, then the statement sets aside memory. For example: subroutine blah(z) include 'SIZE' real x(lx1,ly1,lz1,lelt) common /c1/ y(lx1,ly1,lz1,lelt) real z(lx1,ly1,lz1,lelt) integer e results in two arrays, x and y, be declared to hold n words of memory, where n = lx1*ly1*lz1*lelt The line "real z(...)" does not declare any memory. All three statements indicate how to reference an entry in any of the arrays by the formula: [ z(i,j,k,e) ] = [z(1,1,1,1)] + (i+(j-1)*lx1+(k-1)*lx1*ly1+(e-1)*lx1*ly1*lz1)*wdsize where [.] implies the address of the argument. This formula applies equally to x,y, and z in the above example. f77 does not care about i,j,k, or e (save that they must be integer). It assumes you know what you are doing when you compute an address. Thus the following are almost equivalent: do e=1,nelt do k=1,lz1 do j=1,ly1 do i=1,lx1 x(i,j,k,e)=z(i,j,k,e) enddo enddo enddo enddo n = lx1*ly1*lz1*nelt (Note: nelt, not lelt) do i=1,n x(i,1,1,1) = z(i,1,1,1) enddo The latter, however, is _much_ better than the former. Why? Most compilers will not vectorize more than one loop deep (the "i" loop in the first of the two preceding examples). You thus have a relatively short loop for vectorization; whereas the second, single-loop, form will vectorize. Moreover, the second form makes the code much easier to use. The essential point is that x and z are contiguous arrays --- which is the case throughout nek. NOTE: many users are hesitant about using the 2nd form, despite the fact that it is vastly superior to the first. There is no need to be uneasy about this form, however. It has been used in Nek for over 30 years on hundreds of the world's fastest computers. It is a well-know fortran trick for high performance. Please look through the Nek5000 source for more examples of this type. ________________________________ From: Nek5000-users on behalf of nek5000-users at lists.mcs.anl.gov Sent: Wednesday, August 15, 2018 4:16:15 AM To: nek5000-users at lists.mcs.anl.gov Subject: [Nek5000-users] reshape array Hi all, All average streamwise velocity are stored in this array ?common /avg/ uavg(lx1,ly1,lz1,lelv)? but I want this array to be reshaped into ?common /abcd/ abcd(lx1*ly1*lz1,lelv)? The following didn?t work: common /avg/ uavg(lx1,ly1,lz1,lelv) common /abcd/ abcd(lx1*ly1*lz1,lelv) abcd=reshape(uavg,(/ lx1*ly1*lz1,lelv /)) This is how array reshaping works in fortran. Unfortunately, didn?t work in nek. Anyone knows why? Many thanks in advance for your replies. -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Wed Aug 15 12:16:51 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Wed, 15 Aug 2018 17:16:51 +0000 Subject: [Nek5000-users] reshape array In-Reply-To: References: , Message-ID: PS - please note that the addressing formula should read: [ z(i,j,k,e) ] = [z(1,1,1,1)] + (i-1)+(j-1)*lx1+(k-1)*lx1*ly1+(e-1)*lx1*ly1*lz1)*wdsize ________________________________ From: Nek5000-users on behalf of nek5000-users at lists.mcs.anl.gov Sent: Wednesday, August 15, 2018 9:34:29 AM To: nek5000-users at lists.mcs.anl.gov Subject: Re: [Nek5000-users] reshape array f77 array declarations do either one or two things, depending on whether the array is passed as an argument or is declared within the scope of the routine or function in question. If the array is in a common block or is declared for the first time within a subroutine/function, then the statement sets aside memory. For example: subroutine blah(z) include 'SIZE' real x(lx1,ly1,lz1,lelt) common /c1/ y(lx1,ly1,lz1,lelt) real z(lx1,ly1,lz1,lelt) integer e results in two arrays, x and y, be declared to hold n words of memory, where n = lx1*ly1*lz1*lelt The line "real z(...)" does not declare any memory. All three statements indicate how to reference an entry in any of the arrays by the formula: [ z(i,j,k,e) ] = [z(1,1,1,1)] + (i+(j-1)*lx1+(k-1)*lx1*ly1+(e-1)*lx1*ly1*lz1)*wdsize where [.] implies the address of the argument. This formula applies equally to x,y, and z in the above example. f77 does not care about i,j,k, or e (save that they must be integer). It assumes you know what you are doing when you compute an address. Thus the following are almost equivalent: do e=1,nelt do k=1,lz1 do j=1,ly1 do i=1,lx1 x(i,j,k,e)=z(i,j,k,e) enddo enddo enddo enddo n = lx1*ly1*lz1*nelt (Note: nelt, not lelt) do i=1,n x(i,1,1,1) = z(i,1,1,1) enddo The latter, however, is _much_ better than the former. Why? Most compilers will not vectorize more than one loop deep (the "i" loop in the first of the two preceding examples). You thus have a relatively short loop for vectorization; whereas the second, single-loop, form will vectorize. Moreover, the second form makes the code much easier to use. The essential point is that x and z are contiguous arrays --- which is the case throughout nek. NOTE: many users are hesitant about using the 2nd form, despite the fact that it is vastly superior to the first. There is no need to be uneasy about this form, however. It has been used in Nek for over 30 years on hundreds of the world's fastest computers. It is a well-know fortran trick for high performance. Please look through the Nek5000 source for more examples of this type. ________________________________ From: Nek5000-users on behalf of nek5000-users at lists.mcs.anl.gov Sent: Wednesday, August 15, 2018 4:16:15 AM To: nek5000-users at lists.mcs.anl.gov Subject: [Nek5000-users] reshape array Hi all, All average streamwise velocity are stored in this array ?common /avg/ uavg(lx1,ly1,lz1,lelv)? but I want this array to be reshaped into ?common /abcd/ abcd(lx1*ly1*lz1,lelv)? The following didn?t work: common /avg/ uavg(lx1,ly1,lz1,lelv) common /abcd/ abcd(lx1*ly1*lz1,lelv) abcd=reshape(uavg,(/ lx1*ly1*lz1,lelv /)) This is how array reshaping works in fortran. Unfortunately, didn?t work in nek. Anyone knows why? Many thanks in advance for your replies. -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Sat Aug 18 11:13:12 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Sat, 18 Aug 2018 16:13:12 +0000 Subject: [Nek5000-users] Exodus II to Nek Message-ID: Hello Everyone, I was trying to convert 3-D Exodus II mesh to Nek. I found the following script: exo2nek.f in my files of Nek5000. When I ran it, I got this Error: Can't open included file 'exodusII.inc'. After that, I made ./maketools exo2nek, and then I got the following: makefile:21: recipe for target 'exo2nek.o' failed make[1]: *** [exo2nek.o] Error 1 make[1]: Leaving directory '/home/abdulra5/nek5_svn/trunk/tools/exo2nek' makefile:4: recipe for target 'all' failed make: *** [all] Error 1 Can anybody tell me what are the right steps for conversion? And, If my steps are correct, how can I fix the above issues? Many thanks, Ali Embry-Riddle Aeronautical University -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Sat Aug 18 12:51:06 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Sat, 18 Aug 2018 19:51:06 +0200 Subject: [Nek5000-users] Exodus II to Nek In-Reply-To: References: Message-ID: Are you using the latest release (Nek5000 v17)? > On 18 Aug 2018, at 18:13, "nek5000-users at lists.mcs.anl.gov" wrote: > > can From nek5000-users at lists.mcs.anl.gov Sat Aug 18 15:44:04 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Sat, 18 Aug 2018 20:44:04 +0000 Subject: [Nek5000-users] Exodus II to Nek Message-ID: Thank you for bringing this to my attention, ( ./maketools exo2nek.f) is done successfully now by using Nek5000 v17. However, I still struggle with its implementation on my Exodus II mesh. I am writing (gfortran -c exo2nek.f ) and the following error comes up: Warning: exo2nek.f:3: Illegal preprocessor directive Warning: exo2nek.f:14: Illegal preprocessor directive exo2nek.f:42: Error: Can't open included file 'exodusII.inc'. Is my way of using exo2nek.f correct? Ali Embry-Riddle Aeronautical University -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Sun Aug 19 03:13:36 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Sun, 19 Aug 2018 10:13:36 +0200 Subject: [Nek5000-users] Exodus II to Nek In-Reply-To: References: Message-ID: What are you trying to do? Did you modify the source? What happens if you run ?maketools exo2nek?? On 18 Aug 2018, at 22:43, "nek5000-users at lists.mcs.anl.gov " > wrote: Thank you for bringing this to my attention, ( ./maketools exo2nek.f) is done successfully now by using Nek5000 v17.? ?However, I? still struggle with its implementation on my? Exodus II mesh. I am writing (gfortran -c exo2nek.f ) and the following error comes up: Warning: exo2nek.f:3: Illegal preprocessor directive Warning: exo2nek.f:14: Illegal preprocessor directive exo2nek.f:42: Error: Can't open included file 'exodusII.inc'. Is my way of using exo2nek.f correct?? Ali Embry-Riddle Aeronautical University _______________________________________________ Nek5000-users mailing list Nek5000-users at lists.mcs.anl.gov https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Sun Aug 19 00:54:41 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Sun, 19 Aug 2018 15:54:41 +1000 Subject: [Nek5000-users] Channel Flow 1D/2D energy spectra Message-ID: Hi Nek Users, I am a new user to Nek5000 and I have been playing around with the channel flow example. I have set up an example similar to Kim and Moin. The mean velocity profile seems to agree quite well so I have set up the initial case correctly. Now, my goal is to try and recreate the energy spectra as in the paper above. I am confused as to the best way to go about this, would it be best to obtain output files then do the post processing outside of Nek or can it be done inside Nek as well? My ultimate goal is to be able to cut off some of the higher energy modes and transform it back and feed it at the start of the simulation. Any advice on this would be appreciated as I have been struggling as to how I should proceed in Nek5000. Thanks in advance, David -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Sun Aug 19 09:42:30 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Sun, 19 Aug 2018 14:42:30 +0000 Subject: [Nek5000-users] Exodus II to Nek Message-ID: What are you trying to do? I am just trying to convert exodus ii mesh format to rea. Did you modify the source? Sorry, what source did you mean? I can run all Nek5000 files with no problems. Only exo2nek.f is not working. What happens if you run ?maketools exo2nek?? netcdf ,seacas-exodus, and other files, e.g. exo2nek.o, have been installed. Also, after the compilation process finishes, some warnings appear like "Type mismatch in argument ?j? at (1); passed INTEGER(4) to REAL(8)" or something like that. That is all I know. Again thanks for your help, Ali -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Sun Aug 19 11:16:19 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Sun, 19 Aug 2018 18:16:19 +0200 Subject: [Nek5000-users] Exodus II to Nek In-Reply-To: References: Message-ID: Have you been able to compile exo2nek or not? -----Original message----- > From:nek5000-users at lists.mcs.anl.gov > Sent: Sunday 19th August 2018 16:42 > To: nek5000-users at lists.mcs.anl.gov > Subject: [Nek5000-users] Exodus II to Nek > > What are you trying to do?? > I am just trying to convert exodus ii mesh format to rea. > > Did you modify the source?? > Sorry, what source did you mean? I can run all Nek5000 files with no problems. Only exo2nek.f is not working.? > > What happens if you run ?maketools exo2nek?? > netcdf ,seacas-exodus, and other files, e.g.? exo2nek.o, have been installed. Also, after the compilation process finishes, some warnings appear like? "Type mismatch in argument ?j? at (1); passed INTEGER(4) to REAL(8)"? or something like that.? > > That is all I know. > > Again thanks for your help, > > Ali > > > > _______________________________________________ > Nek5000-users mailing list > Nek5000-users at lists.mcs.anl.gov > https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users From nek5000-users at lists.mcs.anl.gov Sun Aug 19 11:42:55 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Sun, 19 Aug 2018 18:42:55 +0200 Subject: [Nek5000-users] Channel Flow 1D/2D energy spectra In-Reply-To: References: Message-ID: Hi, For most cases, we typically do all these things (statistics, spectra, budgets) outside of Nek5000, on simpler meshes (equidistant or polar meshes for instance). For instance in our paper on pipe flow, we show exactly those 1D and 2D energy spectra. https://link.springer.com/article/10.1007/s10494-013-9482-8 For your purpose however, I would suggest some physical space filter with specific transfer function. That might be the easiest way. Best regards, Philipp On 2018-08-19 07:54, nek5000-users at lists.mcs.anl.gov wrote: > Hi Nek Users, > > I am a new user to Nek5000 and I have been playing around with the > channel flow example. I have set up an example similar to Kim and Moin. > The mean velocity profile seems to agree quite well so I have set up the > initial case correctly.? Now, my goal is to try and recreate the energy > spectra as in the paper above. I am confused as to the best way to go > about this, would it be best to obtain output files then do the post > processing outside of Nek or can it be done inside Nek as well? > > My ultimate goal is to be able to cut off some of the higher energy > modes and transform it back and feed it at the start of the simulation. > Any advice on this would be appreciated as I have been struggling as to > how I should proceed in Nek5000. > > Thanks in advance, > David > > > _______________________________________________ > Nek5000-users mailing list > Nek5000-users at lists.mcs.anl.gov > https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users > From nek5000-users at lists.mcs.anl.gov Sun Aug 19 22:22:24 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Mon, 20 Aug 2018 13:22:24 +1000 Subject: [Nek5000-users] Channel Flow 1D/2D energy spectra In-Reply-To: References: Message-ID: Hi Philipp, Thanks for the reply. So you are saying that I would map the output to a simpler mesh then do the fourier transforms for the spectras? Would you be able to give me a basic idea behind how the spectra could be computed using a simpler mesh? Thanks, William On 20 August 2018 at 02:42, wrote: > Hi, > For most cases, we typically do all these things (statistics, spectra, > budgets) outside of Nek5000, on simpler meshes (equidistant or polar meshes > for instance). For instance in our paper on pipe flow, we show exactly > those 1D and 2D energy spectra. > > https://link.springer.com/article/10.1007/s10494-013-9482-8 > > For your purpose however, I would suggest some physical space filter with > specific transfer function. That might be the easiest way. > > Best regards, > Philipp > > > On 2018-08-19 07:54, nek5000-users at lists.mcs.anl.gov wrote: > >> Hi Nek Users, >> >> I am a new user to Nek5000 and I have been playing around with the >> channel flow example. I have set up an example similar to Kim and Moin. The >> mean velocity profile seems to agree quite well so I have set up the >> initial case correctly. Now, my goal is to try and recreate the energy >> spectra as in the paper above. I am confused as to the best way to go about >> this, would it be best to obtain output files then do the post processing >> outside of Nek or can it be done inside Nek as well? >> >> My ultimate goal is to be able to cut off some of the higher energy modes >> and transform it back and feed it at the start of the simulation. Any >> advice on this would be appreciated as I have been struggling as to how I >> should proceed in Nek5000. >> >> Thanks in advance, >> David >> >> >> _______________________________________________ >> Nek5000-users mailing list >> Nek5000-users at lists.mcs.anl.gov >> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users >> >> _______________________________________________ > Nek5000-users mailing list > Nek5000-users at lists.mcs.anl.gov > https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users > -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Mon Aug 20 02:33:15 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Mon, 20 Aug 2018 09:33:15 +0200 Subject: [Nek5000-users] Channel Flow 1D/2D energy spectra In-Reply-To: References: Message-ID: Hi, how to exactly do it depends on your case. For a channel (or pipe), we typically map the mesh onto a normal rectilinear mesh which is equidistant in the wall-parallel (streamwise/spanwise or axial/azimuthal) directions. This is done via the nek-built-in interpolation routines. however, one needs to check carefully that the new mesh does not lead to interpolation errors close to element boundaries (for curved elements). Once you have everything on a regular mesh, then you just go ahead and to FFTs in the language of choice. Philipp On 2018-08-20 05:22, nek5000-users at lists.mcs.anl.gov wrote: > Hi Philipp, > > Thanks for the reply. So you are saying that I would map the output to a > simpler mesh then do the fourier transforms for the spectras?? Would you > be able to give me a basic idea behind how the spectra could be computed > using a simpler mesh? > > Thanks, > William > > On 20 August 2018 at 02:42, > wrote: > > Hi, > For most cases, we typically do all these things (statistics, > spectra, budgets) outside of Nek5000, on simpler meshes (equidistant > or polar meshes for instance). For instance in our paper on pipe > flow, we show exactly those 1D and 2D energy spectra. > > https://link.springer.com/article/10.1007/s10494-013-9482-8 > > > For your purpose however, I would suggest some physical space filter > with specific transfer function. That might be the easiest way. > > Best regards, > Philipp > > > On 2018-08-19 07:54, nek5000-users at lists.mcs.anl.gov > wrote: > > Hi Nek Users, > > I am a new user to Nek5000 and I have been playing around with > the channel flow example. I have set up an example similar to > Kim and Moin. The mean velocity profile seems to agree quite > well so I have set up the initial case correctly.? Now, my goal > is to try and recreate the energy spectra as in the paper above. > I am confused as to the best way to go about this, would it be > best to obtain output files then do the post processing outside > of Nek or can it be done inside Nek as well? > > My ultimate goal is to be able to cut off some of the higher > energy modes and transform it back and feed it at the start of > the simulation. Any advice on this would be appreciated as I > have been struggling as to how I should proceed in Nek5000. > > Thanks in advance, > David > > > _______________________________________________ > Nek5000-users mailing list > Nek5000-users at lists.mcs.anl.gov > > https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users > > > _______________________________________________ > Nek5000-users mailing list > Nek5000-users at lists.mcs.anl.gov > https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users > > > > > > _______________________________________________ > Nek5000-users mailing list > Nek5000-users at lists.mcs.anl.gov > https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users > From nek5000-users at lists.mcs.anl.gov Mon Aug 20 05:53:11 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Mon, 20 Aug 2018 10:53:11 +0000 Subject: [Nek5000-users] Exodus II to Nek Message-ID: Yes, I assume that was done successfully. Thanks, Ali -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Mon Aug 20 05:54:58 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Mon, 20 Aug 2018 12:54:58 +0200 Subject: [Nek5000-users] Exodus II to Nek In-Reply-To: References: Message-ID: Ok, then you're all set. Just run the tool to convert your EXODUS mesh. -----Original message----- > From:nek5000-users at lists.mcs.anl.gov > Sent: Monday 20th August 2018 12:53 > To: nek5000-users at lists.mcs.anl.gov > Subject: [Nek5000-users] Exodus II to Nek > > > Yes, I assume that was done successfully. > > Thanks, > > Ali > > > _______________________________________________ > Nek5000-users mailing list > Nek5000-users at lists.mcs.anl.gov > https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users From nek5000-users at lists.mcs.anl.gov Mon Aug 20 09:47:27 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Mon, 20 Aug 2018 14:47:27 +0000 Subject: [Nek5000-users] Exodus II to Nek Message-ID: Thanks a lot. Another question please, I am using periodic BC at the ends of the pipe. Is the periodic BC satisfied exactly for all three components of the velocity as it is supposed to? Hint, the flow is not laminar. Ali -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Mon Aug 20 10:01:18 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Mon, 20 Aug 2018 17:01:18 +0200 Subject: [Nek5000-users] Exodus II to Nek In-Reply-To: References: Message-ID: Yes in this case all the velocity components are the same. -----Original message----- > From:nek5000-users at lists.mcs.anl.gov > Sent: Monday 20th August 2018 16:48 > To: nek5000-users at lists.mcs.anl.gov > Subject: [Nek5000-users] Exodus II to Nek > > > > Thanks a lot.? > > Another question please, I am using? periodic BC at the ends of the pipe. Is the periodic BC satisfied exactly for all three components of the velocity as it is supposed to? Hint, the flow is not laminar.? > > Ali > _______________________________________________ > Nek5000-users mailing list > Nek5000-users at lists.mcs.anl.gov > https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users From nek5000-users at lists.mcs.anl.gov Tue Aug 21 02:09:09 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Tue, 21 Aug 2018 17:09:09 +1000 Subject: [Nek5000-users] Channel Flow 1D/2D energy spectra In-Reply-To: References: Message-ID: Thanks so much for your reply. Is it possible for you to elaborate on the specific way to interpolate using the nek5000 built in routine? Say I have run a simulation already and have a number of outputs in ASCII format how would I go about interpolating all the outputs onto this new mesh. Would it be possible, once I have interpolated onto this new mesh to convert back to the old one such that I can restart the simulation using it? Once again, I appreciate your patience as I am still quite new to CFD in general and these questions might seem too basic. Cheers, William On 20 August 2018 at 17:33, wrote: > Hi, > > how to exactly do it depends on your case. For a channel (or pipe), we > typically map the mesh onto a normal rectilinear mesh which is equidistant > in the wall-parallel (streamwise/spanwise or axial/azimuthal) directions. > This is done via the nek-built-in interpolation routines. however, one > needs to check carefully that the new mesh does not lead to interpolation > errors close to element boundaries (for curved elements). Once you have > everything on a regular mesh, then you just go ahead and to FFTs in the > language of choice. > > Philipp > > On 2018-08-20 05:22, nek5000-users at lists.mcs.anl.gov wrote: > >> Hi Philipp, >> >> Thanks for the reply. So you are saying that I would map the output to a >> simpler mesh then do the fourier transforms for the spectras? Would you be >> able to give me a basic idea behind how the spectra could be computed using >> a simpler mesh? >> >> Thanks, >> William >> >> On 20 August 2018 at 02:42, > nek5000-users at lists.mcs.anl.gov>> wrote: >> >> Hi, >> For most cases, we typically do all these things (statistics, >> spectra, budgets) outside of Nek5000, on simpler meshes (equidistant >> or polar meshes for instance). For instance in our paper on pipe >> flow, we show exactly those 1D and 2D energy spectra. >> >> https://link.springer.com/article/10.1007/s10494-013-9482-8 >> >> >> For your purpose however, I would suggest some physical space filter >> with specific transfer function. That might be the easiest way. >> >> Best regards, >> Philipp >> >> >> On 2018-08-19 07:54, nek5000-users at lists.mcs.anl.gov >> wrote: >> >> Hi Nek Users, >> >> I am a new user to Nek5000 and I have been playing around with >> the channel flow example. I have set up an example similar to >> Kim and Moin. The mean velocity profile seems to agree quite >> well so I have set up the initial case correctly. Now, my goal >> is to try and recreate the energy spectra as in the paper above. >> I am confused as to the best way to go about this, would it be >> best to obtain output files then do the post processing outside >> of Nek or can it be done inside Nek as well? >> >> My ultimate goal is to be able to cut off some of the higher >> energy modes and transform it back and feed it at the start of >> the simulation. Any advice on this would be appreciated as I >> have been struggling as to how I should proceed in Nek5000. >> >> Thanks in advance, >> David >> >> >> _______________________________________________ >> Nek5000-users mailing list >> Nek5000-users at lists.mcs.anl.gov >> >> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users >> >> >> _______________________________________________ >> Nek5000-users mailing list >> Nek5000-users at lists.mcs.anl.gov > s.anl.gov> >> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users >> >> >> >> >> >> _______________________________________________ >> Nek5000-users mailing list >> Nek5000-users at lists.mcs.anl.gov >> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users >> >> _______________________________________________ > Nek5000-users mailing list > Nek5000-users at lists.mcs.anl.gov > https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users > -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Tue Aug 21 09:43:56 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Tue, 21 Aug 2018 10:43:56 -0400 Subject: [Nek5000-users] Rotating computational domain Message-ID: Hello Neks, I am an undergraduate student new to Nek and I am working on a simulation studying dynamic stall in a dynamically pitching airfoil. I want to do a pitch and hold simulation at low Reynold's number (Re = 12000) where I rotate the entire computational domain up to about 50 degrees AOA and then hold at 50 degrees, with steady inflow ux = 1. I would like to rotate the domain about the z axis, which passes through the quarter chord location of the airfoil profile (modified NACA 0012). Because of the steep AOA, I would like to stay away from pitching the airfoil within the stationary domain with ALE to avoid too much mesh deformation. To this end, I have been scouring documentation to try and find a method of applying a rotational mesh velocity to the entire domain about the z axis while keeping the flow within the domain at ux = 1. I am feeling very stuck. Others have suggested applying a Coriolis force to the flow, but I don't really see how this would simulate rotation of the entire domain. It seems to me that simulation of a Coriolis force would be acceptable to correct the flow field to always be ux = 1 inside a rotating domain, but I don't see how that would apply a mesh velocity anywhere. Are there any examples where an entire computational domain is rotated that I can look at, or has anybody done similar work who can point me in the right direction? Regards, -Harry -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Tue Aug 21 10:30:20 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Tue, 21 Aug 2018 15:30:20 +0000 Subject: [Nek5000-users] Rotating computational domain In-Reply-To: References: Message-ID: Hi Harry, One simple approach is to use ALE but to have the entire domain pitch, thus preserving your mesh structure. That would properly account for all the accelerations in your non inertial domain. The slightly tricky part would be to determine what BCs you need. You need to be careful about changing the character of the BCs (e.g., from inflow to outflow) in the middle of a computation because that changes which quantities are prescribed and which are unknown. Perhaps one approach would be to have a circular domain with 3/4 of it Dirichlet and 1/4 being outflow (i.e., Neumann for velocity). hth, Paul ________________________________ From: Nek5000-users on behalf of nek5000-users at lists.mcs.anl.gov Sent: Tuesday, August 21, 2018 9:43:56 AM To: nek5000-users at lists.mcs.anl.gov Subject: [Nek5000-users] Rotating computational domain Hello Neks, I am an undergraduate student new to Nek and I am working on a simulation studying dynamic stall in a dynamically pitching airfoil. I want to do a pitch and hold simulation at low Reynold's number (Re = 12000) where I rotate the entire computational domain up to about 50 degrees AOA and then hold at 50 degrees, with steady inflow ux = 1. I would like to rotate the domain about the z axis, which passes through the quarter chord location of the airfoil profile (modified NACA 0012). Because of the steep AOA, I would like to stay away from pitching the airfoil within the stationary domain with ALE to avoid too much mesh deformation. To this end, I have been scouring documentation to try and find a method of applying a rotational mesh velocity to the entire domain about the z axis while keeping the flow within the domain at ux = 1. I am feeling very stuck. Others have suggested applying a Coriolis force to the flow, but I don't really see how this would simulate rotation of the entire domain. It seems to me that simulation of a Coriolis force would be acceptable to correct the flow field to always be ux = 1 inside a rotating domain, but I don't see how that would apply a mesh velocity anywhere. Are there any examples where an entire computational domain is rotated that I can look at, or has anybody done similar work who can point me in the right direction? Regards, -Harry -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Wed Aug 22 15:22:53 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Wed, 22 Aug 2018 22:22:53 +0200 Subject: [Nek5000-users] Rotating computational domain In-Reply-To: References: Message-ID: I guess in the end it amounts to the same as having ALE on the entire domain, but you can do a combination of changing the inflow and adding fictitious forces on the flow. In this way you account for the accelerations explicitly using forcing terms (as opposed to ALE where you get the same "implicitly"). I guess it works, but you might get quite high accelerations further away from the axis. I remember we tried it at some point but I am unsure of the outcome. Philipp On 2018-08-21 17:30, nek5000-users at lists.mcs.anl.gov wrote: > > Hi Harry, > > > One simple approach is to use ALE but to have the entire domain pitch, > > thus preserving your mesh structure. > > > That would properly account for all the accelerations in your non inertial > > domain. > > > The slightly tricky part would be to determine what BCs you need. ?You > > need to be careful about changing the character of the BCs (e.g., from > inflow > > to outflow) ?in the middle of a computation because that changes which > quantities > > are prescribed and which are unknown. ? Perhaps one approach would be > > to have a circular domain with 3/4 of it Dirichlet and 1/4 being outflow > (i.e., > > Neumann for velocity). > > > hth, > > > Paul > > > ------------------------------------------------------------------------ > *From:* Nek5000-users on > behalf of nek5000-users at lists.mcs.anl.gov > *Sent:* Tuesday, August 21, 2018 9:43:56 AM > *To:* nek5000-users at lists.mcs.anl.gov > *Subject:* [Nek5000-users] Rotating computational domain > Hello Neks, > > I am an undergraduate student new to Nek and I am working on a > simulation studying dynamic stall in a dynamically pitching airfoil.? I > want to do a pitch and hold simulation at low Reynold's number (Re = > 12000) where I rotate the entire computational domain up to about 50 > degrees AOA and then hold at 50 degrees, with steady inflow ux = 1.? I > would like to rotate the domain about the z axis, which passes through > the quarter chord location of the airfoil profile (modified NACA 0012). > > Because of the steep AOA, I would like to stay away from pitching the > airfoil within the stationary domain with ALE to avoid too much mesh > deformation.? To this end, I have been scouring documentation to try and > find a method of applying a rotational mesh velocity to the entire > domain about the z axis while keeping the flow within the domain at ux = > 1.? I am feeling very stuck.? Others have suggested applying a Coriolis > force to the flow, but I don't really see how this would simulate > rotation of the entire domain.? It seems to me that simulation of a > Coriolis force would be acceptable to correct the flow field to always > be ux = 1 inside a rotating domain, but I don't see how that would apply > a mesh velocity anywhere. > > Are there any examples where an entire computational domain is rotated > that I can look at, or has anybody done similar work who can point me in > the right direction? > > Regards, > -Harry > > > _______________________________________________ > Nek5000-users mailing list > Nek5000-users at lists.mcs.anl.gov > https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users > From nek5000-users at lists.mcs.anl.gov Thu Aug 23 14:46:34 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Thu, 23 Aug 2018 15:46:34 -0400 Subject: [Nek5000-users] Regarding spatial resolution Message-ID: Hey Neks, I have a very basic question about the spatial resolution of Nek5000. Suppose my elements in the domain are squares of unit length. If my GLL points used are 17 (or order of the polynomial used is 16), what is the least spatial length resolved by the code? As an approximate, can one use 1/17 units? Is there a way to calculate this least spatial length being resolved? Thanks, Saikat -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Fri Aug 24 00:11:45 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Fri, 24 Aug 2018 10:41:45 +0530 Subject: [Nek5000-users] ICEM CFD mesh conversion in NEK5000 Message-ID: Hi Neks, I have generated a mesh in ICEM CFD software. And exported mesh in .exo format. Then I have used exo2nex to convert mesh. while running the case one error is showing. That error is shown below 0 ERROR: Vanishing Jacobian near 5th node of element 1. 1.10361832315621911E-002 -6.75425029014820044E-003 0 xyz: 2.06376E-01 3.94255E-02 0 xyz: 2.27305E-01 3.94255E-02 0 0.0000E+00 Write checkpoint 0 0.0000E+00 OPEN: xyzexodus.fld01 Jac error 1, setting p66=4, ifxyo=t an error occured: dying ... I am not able to solve this problem. Kindly help me with this. Thank you Alok Mishra Research Scholar Computational Propulsion Lab Aerospace Department IIT Kanpur -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Fri Aug 24 07:15:29 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Fri, 24 Aug 2018 20:15:29 +0800 Subject: [Nek5000-users] About TST_WSCAL Message-ID: hello Neks. I am a Nek5000 user and want to test nek5000 scalability,so I try to rewirte the file. I modify the makenek file: ========================================== FFLAGS="-DTST_WSCAL" CFLAGS=" " ========================================== I added the statment in reader_par.f ========================================== param(151) = 30 param(150) = 50 ========================================== so i try to run the demo ethier,but i got the error iformation like these: ========================================== Step 42, t= 4.2000000E-03, DT= 1.0000000E-04, C= 1.002 1.8351E+01 4.4267E-01 Solving for fluid 42 PRES gmres 30 1.4718E-09 4.1884E+01 1.0000E-08 8.2129E-02 1.4073E-01 F 42 Hmholtz VELX 50 3.5103E-04 2.0863E+02 1.0000E-12 42 Hmholtz VELY 50 1.6061E-10 1.5756E+02 1.0000E-12 42 Hmholtz VELZ 50 3.0524E+02 9.4242E+01 1.0000E-12 L1/L2 DIV(V) 9.3378E-01 2.3756E+02 L1/L2 QTL 0.0000E+00 0.0000E+00 L1/L2 DIV(V)-QTL 9.3378E-01 2.3756E+02 WARNING: DIV(V)-QTL too large! 42 Fluid done 4.2000E-03 3.1138E-01 CFL, Ctarg! 84.587414707615267 0.5 43 4.2000E-03 Write checkpoint FILE:/home/export/online1/wangxm/zhouzhifeng/Nek5000demo/run/ethier/ethier0.f00001 43 4.2000E-03 done :: Write checkpoint file size = 0.44 MB avg data-throughput = 6.1MB/s io-nodes = 4 ========================================== it just runs 40 steps instead of 1000 steps , how can i deal with that? Thank you so much ~ -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Fri Aug 24 10:26:47 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Fri, 24 Aug 2018 11:26:47 -0400 Subject: [Nek5000-users] Rotating computational domain In-Reply-To: References: Message-ID: Hi Paul and Phillip, Thanks for your replies. I will try to apply ALE to the entire domain and play with the BCs to try and get a result. I've already rejected the standard C-mesh for airfoils in favor of an unstructured circular domain because the C-mesh boundaries are not conducive to rotating the entire domain. If I'm unsuccessful with this approach I will try to apply a rotating inflow and add a Coriolis force to correct. In either case, if everything works out I would like to submit a very small example case to the Nek documentation to help others in their quest for a rotating domain. I'll post back here if I run into trouble, thanks again for your insight! -Harry On Tue, Aug 21, 2018 at 11:30 AM, wrote: > > Hi Harry, > > > One simple approach is to use ALE but to have the entire domain pitch, > > thus preserving your mesh structure. > > > That would properly account for all the accelerations in your non inertial > > domain. > > > The slightly tricky part would be to determine what BCs you need. You > > need to be careful about changing the character of the BCs (e.g., from > inflow > > to outflow) in the middle of a computation because that changes which > quantities > > are prescribed and which are unknown. Perhaps one approach would be > > to have a circular domain with 3/4 of it Dirichlet and 1/4 being outflow > (i.e., > > Neumann for velocity). > > > hth, > > > Paul > > > ------------------------------ > *From:* Nek5000-users on behalf > of nek5000-users at lists.mcs.anl.gov > *Sent:* Tuesday, August 21, 2018 9:43:56 AM > *To:* nek5000-users at lists.mcs.anl.gov > *Subject:* [Nek5000-users] Rotating computational domain > > Hello Neks, > > I am an undergraduate student new to Nek and I am working on a simulation > studying dynamic stall in a dynamically pitching airfoil. I want to do a > pitch and hold simulation at low Reynold's number (Re = 12000) where I > rotate the entire computational domain up to about 50 degrees AOA and then > hold at 50 degrees, with steady inflow ux = 1. I would like to rotate the > domain about the z axis, which passes through the quarter chord location of > the airfoil profile (modified NACA 0012). > > Because of the steep AOA, I would like to stay away from pitching the > airfoil within the stationary domain with ALE to avoid too much mesh > deformation. To this end, I have been scouring documentation to try and > find a method of applying a rotational mesh velocity to the entire domain > about the z axis while keeping the flow within the domain at ux = 1. I am > feeling very stuck. Others have suggested applying a Coriolis force to the > flow, but I don't really see how this would simulate rotation of the entire > domain. It seems to me that simulation of a Coriolis force would be > acceptable to correct the flow field to always be ux = 1 inside a rotating > domain, but I don't see how that would apply a mesh velocity anywhere. > > Are there any examples where an entire computational domain is rotated > that I can look at, or has anybody done similar work who can point me in > the right direction? > > Regards, > -Harry > > _______________________________________________ > Nek5000-users mailing list > Nek5000-users at lists.mcs.anl.gov > https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users > > -- Harry E. Werner IV Secretary Clarkson University SCUBA Club *Cell:* (716) 570-4023 -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Mon Aug 27 09:19:35 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Mon, 27 Aug 2018 10:19:35 -0400 Subject: [Nek5000-users] Regarding spatial resolution In-Reply-To: References: Message-ID: Hi Neks, Just following up on this question. Thank you. Saikat On Thu, Aug 23, 2018 at 3:46 PM, Saikat Mukherjee wrote: > Hey Neks, > > I have a very basic question about the spatial resolution of Nek5000. > Suppose my elements in the domain are squares of unit length. If my GLL > points used are 17 (or order of the polynomial used is 16), what is the > least spatial length resolved by the code? As an approximate, can one use > 1/17 units? Is there a way to calculate this least spatial length being > resolved? > > Thanks, > Saikat > > > > -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Mon Aug 27 09:22:06 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Mon, 27 Aug 2018 16:22:06 +0200 Subject: [Nek5000-users] Regarding spatial resolution In-Reply-To: References: Message-ID: Just check in eg matlab the spacing of the Legendre nodes in the element centre. If you want to be conservative, this is the largest grid spacing. On August 27, 2018 4:19:35 PM GMT+02:00, nek5000-users at lists.mcs.anl.gov wrote: >Hi Neks, > >Just following up on this question. Thank you. > >Saikat > > > > > >On Thu, Aug 23, 2018 at 3:46 PM, Saikat Mukherjee >wrote: > >> Hey Neks, >> >> I have a very basic question about the spatial resolution of Nek5000. >> Suppose my elements in the domain are squares of unit length. If my >GLL >> points used are 17 (or order of the polynomial used is 16), what is >the >> least spatial length resolved by the code? As an approximate, can one >use >> 1/17 units? Is there a way to calculate this least spatial length >being >> resolved? >> >> Thanks, >> Saikat >> >> >> >> -- Sent from my Android device with K-9 Mail. Please excuse my brevity. -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Tue Aug 28 12:08:58 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Tue, 28 Aug 2018 17:08:58 +0000 Subject: [Nek5000-users] Statistics toolbox for Nek5000 Message-ID: Hello everyone, I found this statistics toolbox for Nek5000 https://github.com/Mopolino8/StatsToolbox However, according to the accompanying PDF documentation, there should be some folders called cpost3d, post3d and post2d, which are not in the repository. Does anyone have access to those folders? I am trying to compute transport equation budget terms but part of my results are strange, so I want to compare how the statistics toolbox computes them to verify if there is bug in my code. Thank you! Juan Diego -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Tue Aug 28 12:18:30 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Tue, 28 Aug 2018 19:18:30 +0200 Subject: [Nek5000-users] Statistics toolbox for Nek5000 In-Reply-To: References: Message-ID: Hi, we are working on a version of this toolbox that is compatible with the latest version of Nek5000, and should deliver statistics properly oriented in any coordinate system one needs (e.g. Reynolds stresses tangential/normal to surfaces), in 2D (assuming one homogeneous direction) and 3D. There is also a (slightly outdated) manual of the toolbox here: https://www.osti.gov/biblio/1349052-turbulence-statistics-spectral-element-code-toolbox-high-fidelity-simulations We will hopefully be able to provide the improved package soon. Philipp On 2018-08-28 19:08, nek5000-users at lists.mcs.anl.gov wrote: > Hello everyone, > > > I found this statistics toolbox for Nek5000 > https://github.com/Mopolino8/StatsToolbox > > However, according to the accompanying PDF documentation, there should > be some folders called cpost3d, post3d and post2d, which are not in the > repository. Does anyone have access to those folders? > > > I am trying to compute transport equation budget terms but part of my > results are strange, so I want to compare how the statistics toolbox > computes them to verify if there is bug in my code. > > > Thank you! > > > Juan Diego > > > > _______________________________________________ > Nek5000-users mailing list > Nek5000-users at lists.mcs.anl.gov > https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users > From nek5000-users at lists.mcs.anl.gov Wed Aug 29 10:03:02 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Wed, 29 Aug 2018 15:03:02 +0000 Subject: [Nek5000-users] Freestream BC: Dirichlet/Neumann BC Message-ID: Dear Nek users, I am wondering is there a way to assign the freestream BC as ?U = expression and dv/dy = expression? , instead of assigning U and V directly? Could anyone please help me on this? Thanks in advance -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Wed Aug 29 12:40:01 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Wed, 29 Aug 2018 19:40:01 +0200 Subject: [Nek5000-users] Freestream BC: Dirichlet/Neumann BC In-Reply-To: References: Message-ID: Within certain limits, yes. You can check the "ON" or "on" boundary condition in Nek, which is a combination of specified total stress (the "o" part where captial O just means zero total stress) and "N" which means that the velocity tangential to the boundary can be specified. A bit more on how to use on can be found in this post: https://lists.mcs.anl.gov/mailman/htdig/nek5000-users/2018-August/005569.html Philipp On 2018-08-29 17:03, nek5000-users at lists.mcs.anl.gov wrote: > Dear Nek users, > > I am wondering is there a way to assign the freestream BC as ?U = > expression and dv/dy = expression? , instead of assigning U and V > directly? Could anyone please help me on this? > > Thanks in advance > > > > _______________________________________________ > Nek5000-users mailing list > Nek5000-users at lists.mcs.anl.gov > https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users > From nek5000-users at lists.mcs.anl.gov Wed Aug 29 22:34:25 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Thu, 30 Aug 2018 06:34:25 +0300 Subject: [Nek5000-users] =?utf-8?q?The_number_of_adjacent_element?= Message-ID: Hi, Neks! Could I easy identify the number of adjacent element? For example, if I know, that now I am in the "e=25" element, could I know "e" neighbors? I know, that the mesh is globaly unstructured, but anyway? Best regards, Valdemar -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Thu Aug 30 01:21:00 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Thu, 30 Aug 2018 08:21:00 +0200 Subject: [Nek5000-users] The number of adjacent element In-Reply-To: References: Message-ID: Not that I know. What are you trying to do? -----Original message----- > From:nek5000-users at lists.mcs.anl.gov > Sent: Thursday 30th August 2018 5:34 > To: nek5000-users > Subject: [Nek5000-users] The number of adjacent element > > Hi, Neks! > > Could I easy identify the number of adjacent element? For example, if I know, that now I am in the "e=25" element, could I know "e" neighbors? I know, that the mesh is globaly unstructured, but anyway? > > Best regards, > Valdemar > _______________________________________________ > Nek5000-users mailing list > Nek5000-users at lists.mcs.anl.gov > https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users From nek5000-users at lists.mcs.anl.gov Thu Aug 30 05:40:03 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Thu, 30 Aug 2018 10:40:03 +0000 Subject: [Nek5000-users] Exodus II to Nek Message-ID: Sorry for asking again, but I need to check that the boundary conditions are all satisfied. I have checked the velocities, the only axial velocity is exactly same. That is may be, I am applying the periodic boundary conditions in the axial direction only, or the way I calculated the azimuthal and radial velocities is not sufficient, is that right? Hint, I drive the flow using a force like the way of turbChannel example. Also,I am using VisIt to calculate and plot the velocity components. My pipe length is 5D, which I think it is sufficient to capture all turbulence scales. Ali Embry-Riddle Aeronautical University -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Thu Aug 30 06:12:46 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Thu, 30 Aug 2018 13:12:46 +0200 Subject: [Nek5000-users] Exodus II to Nek In-Reply-To: References: Message-ID: Note, the exo2nek converter doesn't support periodic boundary conditions. -----Original message----- > From:nek5000-users at lists.mcs.anl.gov > Sent: Thursday 30th August 2018 12:42 > To: nek5000-users at lists.mcs.anl.gov > Subject: [Nek5000-users] Exodus II to Nek > > > Sorry for asking again, but I need to check? that the?boundary conditions are all?satisfied.? > > I have checked the velocities, the only axial velocity is exactly same. That is may be, I am applying the periodic boundary conditions in the axial direction only, or the way I calculated the azimuthal and radial velocities is not sufficient, is that right?? > > Hint, I drive the flow using a force like the way of turbChannel example. Also,I am using VisIt to calculate and plot the velocity components. My pipe length is 5D, which I think it is sufficient to capture all turbulence scales.? > > Ali > Embry-Riddle Aeronautical University > > > _______________________________________________ > Nek5000-users mailing list > Nek5000-users at lists.mcs.anl.gov > https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users From nek5000-users at lists.mcs.anl.gov Thu Aug 30 11:04:33 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Thu, 30 Aug 2018 16:04:33 +0000 Subject: [Nek5000-users] Statistics toolbox for Nek5000 Message-ID: Dear Philipp, Thanks for the reply. Do you have the older version of the statistics toolbox? I'm using the old version of Nek anyways. In the repository that I found, there is only the 'compile' and 'run' directories, but there is not 'post2d' directory, which according to the manual that you sent is where the subroutines for computing budget terms are located. As I mentioned before, what I would like to do is to compare the code against mine to make sure there are no bugs. Thank you, Juan Diego -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Thu Aug 30 14:40:14 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Thu, 30 Aug 2018 19:40:14 +0000 Subject: [Nek5000-users] The number of adjacent element In-Reply-To: References: Message-ID: Something like: real x(lx1,ly1,lz1,lelt) integer e real eg nxyz = lx1*ly1*lz1 do e=1,nelv eg = lglel(e) call cfill(x(1,1,1,e),eg, nxyz) call cfill(y(1,1,1,e),eg, nxyz) enddo call dssum(x,nx1,ny1,nz1) do e=1,nelv eg= -lglel(e) call cadd(x(1,1,1,e),eg,nxyz) enddo Now the faces tell you which faces you're connected to. To get edges and corners is a bit trickier, but not hard -- use dsop(x,'min') and max etc. to discriminate... A few passes through the process will reveal all the connections. hth Paul ________________________________ From: Nek5000-users on behalf of nek5000-users at lists.mcs.anl.gov Sent: Wednesday, August 29, 2018 10:34:25 PM To: nek5000-users Subject: [Nek5000-users] The number of adjacent element Hi, Neks! Could I easy identify the number of adjacent element? For example, if I know, that now I am in the "e=25" element, could I know "e" neighbors? I know, that the mesh is globaly unstructured, but anyway? Best regards, Valdemar -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Thu Aug 30 15:52:23 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Thu, 30 Aug 2018 22:52:23 +0200 Subject: [Nek5000-users] Statistics toolbox for Nek5000 In-Reply-To: References: Message-ID: Hi Juan Diego, As we are talking old version, perhaps we can discuss that off list. Please send me an email directly. Best regards, Philipp On 2018-08-30 18:04, nek5000-users at lists.mcs.anl.gov wrote: > Dear Philipp, > > > Thanks for the reply. Do you have the older version of the statistics > toolbox? I'm using the old version of Nek anyways. > > > In the repository that I found, there is only the 'compile' and 'run' > directories, but there is not 'post2d' directory, which according to the > manual that you sent is where the subroutines for computing budget terms > are located. As I mentioned before, what I would like to do is to > compare the code against mine to make sure there are no bugs. > > > Thank you, > > > Juan Diego > > > > _______________________________________________ > Nek5000-users mailing list > Nek5000-users at lists.mcs.anl.gov > https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users > From nek5000-users at lists.mcs.anl.gov Fri Aug 31 07:27:51 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Fri, 31 Aug 2018 20:27:51 +0800 (CST) Subject: [Nek5000-users] Parameter settings on filterWeight and filterCutoffRatio Message-ID: Hi neks, Recently I am working on an LES simulation in an annular pipe to see how transverse velocity goes with Re increasing. But I am quite wondering how I should set filterWeight and filterCutoffRatio in my example while in the turbChannel demo they are selected to 10 an 0.9 respectively as proposed value. They should be sensitive parameters in LES simulation, don't they? Is there any references concerned about them to help me see them more clearly? If it is convenient for you could you please reply me a url to the reference? Thank you so much for your assistence. best regard -- JU Haoran Department of Nuclear Science and Technology, School of Energy and Power Engineering, Xi'an Jiaotong University, 710049. No.28 Xianning West Road, Xi'an, Shanxi Province, China. Email: juhaoran012 at 163.com -------------- next part -------------- An HTML attachment was scrubbed... URL: From nek5000-users at lists.mcs.anl.gov Fri Aug 31 19:39:27 2018 From: nek5000-users at lists.mcs.anl.gov (nek5000-users at lists.mcs.anl.gov) Date: Sat, 1 Sep 2018 08:39:27 +0800 Subject: [Nek5000-users] Parameter settings on filterWeight and filterCutoffRatio Message-ID: Hi neks, Recently I am working on an LES simulation in an annular pipe to see how transverse velocity goes with Re increasing. But I am quite wondering how I should set filterWeight and filterCutoffRatio in my example while in the turbChannel demo they are selected to 10 an 0.9 respectively as proposed value. They should be sensitive parameters in LES simulation, don't they? Is there any references concerned about them to help me see them more clearly? If it is convenient for you could you please reply me a url to the reference? Thank you so much for your assistence. best regard -- -------------- next part -------------- An HTML attachment was scrubbed... URL: