[Nek5000-users] Pipe with expansion
nek5000-users at lists.mcs.anl.gov
nek5000-users at lists.mcs.anl.gov
Fri Jan 24 06:02:12 CST 2014
Kamal,
1) yes
2) standard approach to seeing vorticity would be something
like the following in userchk
parameter (lt=lx1*ly1*lz1*lelt)
common /myjunk/ vort(lt,3),w1(lt),w2(lt)
logical ifxyt
integer ivout ! flag to turn geometry on/off for VisIt
save ivout
data ivout /0/
if (mod(istep,iostep).eq.0) then
call comp_vort3(vort,w1,w2,vx,vy,vz)
ifxyt = ifxyo ! put geometry into first vrt file
ifxyo = .false.
if (ivout.eq.0) ifxyo = .true.
ivout = 1
call outpost(vort(1,1),vort(1,2),vort(1,3),pr,t,'vrt')
ifxyo = ifxyt ! restore ifxyo flag to original state
endif
If your session name is blah, this piece of code will put
vorticity into a sequence of files vrtblah0.f0000n
You can instead ignore the vrt prefix and the part about the
geometry with a simpler code
parameter (lt=lx1*ly1*lz1*lelt)
common /myjunk/ vort(lt,3),w1(lt),w2(lt)
if (mod(istep,iostep).eq.0) then
call comp_vort3(vort,w1,w2,vx,vy,vz)
call outpost(vort(1,1),vort(1,2),vort(1,3),pr,t,'vrt')
endif
I usually go for this latter approach, but the choice is
totally up to you.
Paul
On Fri, 24 Jan 2014, nek5000-users at lists.mcs.anl.gov wrote:
> Hello Paul,
>
> Thanks for your reply. I am looking into the .usr file for defining the
> set_obj ().
>
> 1) Could you please tell me what is 'Enter the number of levels ?' in n2to3
>
> is it the number of elements in Z direction ?
>
> 2) As you said about storing the computed vorticity in velocity field to view
> in VisIT, I found the routine to compute the vorticity but I am stuck about
> adding it to the velocity filed to VisIT ? could you please tell me how it
> works or any example which stores vorticity to the .fld file as a separate
> variable.
>
>
> Thank you
>
> Kamal
>
>
> On 22/01/2014 16:53, nek5000-users at lists.mcs.anl.gov wrote:
>> Axial viscous stress is given by torq_calc -- that's no problem whatsoever.
>> You get a number as a
>> function of time.
>>
>> You can even get stresses on multiple subsets of the geometry (e.g., if you
>> had multiple branches
>> in the domain or multiple cylinders. The drag, which is a byproduct of
>> the torque computation (which
>> you can ignore), is given in terms of the viscous and pressure components
>> separately and as the
>> sum of the two.
>>
>> You can identify domain boundaries by checking the boundary conditions.
>> Here, I recommend
>> looking at the set_obj routines in several of the /example cases.
>>
>>
>> ________________________________________
>> From: nek5000-users-bounces at lists.mcs.anl.gov
>> [nek5000-users-bounces at lists.mcs.anl.gov] on behalf of
>> nek5000-users at lists.mcs.anl.gov [nek5000-users at lists.mcs.anl.gov]
>> Sent: Wednesday, January 22, 2014 9:37 AM
>> To: nek5000-users at lists.mcs.anl.gov
>> Subject: Re: [Nek5000-users] Pipe with expansion
>>
>> Hello Paul
>>
>> I was thinking about taking the tangential velocity near to the wall so
>> that I can figure out my length of the recirculation region.
>>
>> Is it possible for me to access the boundary elements of the mesh ??? so
>> that I can take the boundary element and then obtain the velocity at that
>> point so that I can figure out the length of my recirculation region.
>>
>> or take the *.fld file and read it to plot the datas I need.
>>
>>
>> I also want to calculate the axial viscous force acting on the entire pipe.
>>
>> which is given by
>>
>> C_v = F^v / ( d^2 * rho * U^2 ) = double integral ( 1/Re * (du / dr) )
>> dtheta dz
>>
>>
>> On Jan 22, 2014, at 4:07 PM, nek5000-users at lists.mcs.anl.gov wrote:
>>
>>> Hi Kamal,
>>>
>>> As I thought about it some more, if you're interested in the local wall
>>> shear stress
>>> magnitude I'm quite certain you can get this by plotting the magnitude of
>>> vorticity
>>> on the surface in question. (Note that the sign of the WSS, which in
>>> fact is a tensor
>>> or a vector when restricted to a given surface, is lost in this process,
>>> but that might
>>> not be relevant for your needs.) If that works, then you can readily
>>> compute the
>>> vorticity using one of the routines in nek and store the result in a
>>> velocity field, then
>>> view that field with VisIt. Of course WSS will require multiplication by
>>> viscosity.
>>>
>>> hth,
>>>
>>> Paul
>>>
>>> ________________________________________
>>> From: nek5000-users-bounces at lists.mcs.anl.gov
>>> [nek5000-users-bounces at lists.mcs.anl.gov] on behalf of
>>> nek5000-users at lists.mcs.anl.gov [nek5000-users at lists.mcs.anl.gov]
>>> Sent: Tuesday, January 21, 2014 10:33 AM
>>> To: nek5000-users at lists.mcs.anl.gov
>>> Subject: Re: [Nek5000-users] Pipe with expansion
>>>
>>> Hi paul,
>>>
>>> can I make this to be drag or shear quantities to be return to the a
>>> separate file so that it will easy for me to plot.
>>>
>>> By the way it gives the integral quantity. Think for example I need to
>>> find the shear stress on the wall from the inlet to outlet at a
>>> particular time = 2 . How can I do that ?
>>>
>>> Is there way to find the number of elements in x,y and z direction ?
>>>
>>> On 21/01/2014 17:32, nek5000-users at lists.mcs.anl.gov wrote:
>>>> Hi Kamal,
>>>>
>>>> Your integrated drag quantities should be written to the logfile
>>>> (stdout),
>>>> assuming you've set the arguments in the call to be .true.
>>>>
>>>> Paul
>>>>
>>>> On Tue, 21 Jan 2014, nek5000-users at lists.mcs.anl.gov wrote:
>>>>
>>>>> Hi Paul,
>>>>>
>>>>> I checked the set_obj subroutine and implemented one in my .USR file.
>>>>> The code seem to run without any errors but I don't find where these
>>>>> variables are getting stored.
>>>>>
>>>>> I use VisIT to visualize my output, even there was no change in it.
>>>>>
>>>>> do I have to define my own output file and write the variables out ?
>>>>>
>>>>> Thanks,
>>>>>
>>>>> Kamal.
>>>>>
>>>>>
>>>>> On 20/01/2014 21:52, nek5000-users at lists.mcs.anl.gov wrote:
>>>>>> Hi Kamal,
>>>>>>
>>>>>> You'll need to compute your own tke by manipulating the
>>>>>> velocity fields.
>>>>>>
>>>>>> You can get running averages of the requisite quantities
>>>>>> via calls to "avg_all" which is found in navier5.f
>>>>>>
>>>>>> You can compute shear stress on the wall simply by computing
>>>>>> the drag on the wall, which can be done via a call to torque_calc(),
>>>>>> also found in navier5.f
>>>>>>
>>>>>> If you cd to /examples and type:
>>>>>>
>>>>>> grep torq */*.usr
>>>>>>
>>>>>> you'll find many examples of calls to torque_calc. You simply
>>>>>> need to prescribe the surfaces on which shear is to be integrated.
>>>>>>
>>>>>> I typically write a routine "set_obj" to identify such surfaces
>>>>>> on the first call to usrchk.
>>>>>>
>>>>>> grep set_obj */*.usr
>>>>>>
>>>>>> will show similar examples.
>>>>>>
>>>>>> I would recommend trying this for laminar Poiseiulle flow in
>>>>>> a very simple channel just to check that your calls are properly
>>>>>> set.
>>>>>>
>>>>>> Best,
>>>>>>
>>>>>> Paul
>>>>>>
>>>>>>
>>>>>> On Mon, 20 Jan 2014, nek5000-users at lists.mcs.anl.gov wrote:
>>>>>>
>>>>>>> Hi Paul,
>>>>>>>
>>>>>>> Thanks and that helped.
>>>>>>>
>>>>>>> Where can I find the variables like Turbulent KE , shear stress on
>>>>>>> the wall. ?
>>>>>>>
>>>>>>> Do i have to activate some parameters for calculating them ?
>>>>>>>
>>>>>>> If I had to plot them.
>>>>>>>
>>>>>>> Thanks,
>>>>>>> Kamal
>>>>>>>
>>>>>>>
>>>>>>> On Jan 20, 2014, at 5:41 AM, nek5000-users at lists.mcs.anl.gov wrote:
>>>>>>>
>>>>>>>> Kamal,
>>>>>>>>
>>>>>>>> Looks good.
>>>>>>>>
>>>>>>>> I'm guessing that one further refinement would be:
>>>>>>>>
>>>>>>>> if (z.gt.z0) scale = 1 + (smax-1)*(z-z0)/(z1-z0)
>>>>>>>> if (z.gt.z1) scale = smax
>>>>>>>>
>>>>>>>> which would yield
>>>>>>>>
>>>>>>>> scale = 1 when z=z0
>>>>>>>> scale = smax when z >= z1
>>>>>>>>
>>>>>>>> Paul
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> On Sun, 19 Jan 2014, nek5000-users at lists.mcs.anl.gov wrote:
>>>>>>>>
>>>>>>>>> Hi paul,
>>>>>>>>>
>>>>>>>>> The code works fine, but there should be a small change thats has
>>>>>>>>> to be done
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> if (z.gt.z0) scale = 1 + (z /(z1-z0 )))
>>>>>>>>> if (z.gt.z1) scale = smax
>>>>>>>>>
>>>>>>>>> This creates a perfect diverging pipe.
>>>>>>>>>
>>>>>>>>> Thanks for the help paul.
>>>>>>>>>
>>>>>>>>> Kamal
>>>>>>>>>
>>>>>>>>> On Jan 20, 2014, at 12:09 AM, nek5000-users at lists.mcs.anl.gov wrote:
>>>>>>>>>
>>>>>>>>>> Hi paul,
>>>>>>>>>>
>>>>>>>>>> If I am not wrong,
>>>>>>>>>> I make a mesh with three straight pipes( inlet, divergent,
>>>>>>>>>> outlet ) connected together via n2to3 so that I know the element
>>>>>>>>>> connectivity places of the divergent section (z0,z1) and use the
>>>>>>>>>> section what you gave
>>>>>>>>>>
>>>>>>>>>> Thank you for the code
>>>>>>>>>>
>>>>>>>>>> Kamal
>>>>>>>>>>
>>>>>>>>>> On Jan 19, 2014, at 8:45 PM, nek5000-users at lists.mcs.anl.gov wrote:
>>>>>>>>>>
>>>>>>>>>>> Kamal,
>>>>>>>>>>>
>>>>>>>>>>> I would do the following in usrdat2():
>>>>>>>>>>>
>>>>>>>>>>> n=nx1*ny1*nz1*nelt
>>>>>>>>>>>
>>>>>>>>>>> do i=1,n
>>>>>>>>>>> x=xm1(i,1,1,1)
>>>>>>>>>>> y=ym1(i,1,1,1)
>>>>>>>>>>> z=ym1(i,1,1,1)
>>>>>>>>>>> scale = 1.
>>>>>>>>>>> if (z.gt.z0) scale = smax*(z-z0/(z1-z0)
>>>>>>>>>>> if (z.gt.z1) scale = smax
>>>>>>>>>>> xm1(i,1,1,1) = scale*x
>>>>>>>>>>> ym1(i,1,1,1) = scale*y
>>>>>>>>>>> enddo
>>>>>>>>>>>
>>>>>>>>>>> Paul
>>>>>>>>>>>
>>>>>>>>>>> Make certain that z1 and z0 correspond to z values
>>>>>>>>>>> that precisely coincide with element interfaces.
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> On Sun, 19 Jan 2014, nek5000-users at lists.mcs.anl.gov wrote:
>>>>>>>>>>>
>>>>>>>>>>>> Hi Paul,
>>>>>>>>>>>>
>>>>>>>>>>>> I looked into the Peris example but It is so what same like
>>>>>>>>>>>> the stenosis example with a Cosine deformation.
>>>>>>>>>>>>
>>>>>>>>>>>> In my case it is a pipe with conical divergent. I tried to
>>>>>>>>>>>> play around the variables Xm1, Ym1 and Zm1 but the mapping
>>>>>>>>>>>> doesn't go well.
>>>>>>>>>>>>
>>>>>>>>>>>> Could you please help me with this.
>>>>>>>>>>>>
>>>>>>>>>>>> Thank you,
>>>>>>>>>>>>
>>>>>>>>>>>> Kamal
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> On Jan 18, 2014, at 7:26 PM, nek5000-users at lists.mcs.anl.gov
>>>>>>>>>>>> wrote:
>>>>>>>>>>>>
>>>>>>>>>>>>> Hi Paul,
>>>>>>>>>>>>>
>>>>>>>>>>>>> I looked at the Helix and stenosis example but they are using
>>>>>>>>>>>>> cosine functions to deform
>>>>>>>>>>>>>
>>>>>>>>>>>>> I tried to use a tangent function but it bends the whole pipe.
>>>>>>>>>>>>>
>>>>>>>>>>>>> I dint look at peris example .
>>>>>>>>>>>>>
>>>>>>>>>>>>> I will take a look at it and let you know.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Thank you
>>>>>>>>>>>>>
>>>>>>>>>>>>> Kamal
>>>>>>>>>>>>>
>>>>>>>>>>>>> On Jan 18, 2014, at 7:22 PM, nek5000-users at lists.mcs.anl.gov
>>>>>>>>>>>>> wrote:
>>>>>>>>>>>>>
>>>>>>>>>>>>>> Kamal,
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Have you looked at the peris example? The usr file there
>>>>>>>>>>>>>> shows how to deform
>>>>>>>>>>>>>> a pipe geometry.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Paul
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> From: nek5000-users-bounces at lists.mcs.anl.gov
>>>>>>>>>>>>>> [nek5000-users-bounces at lists.mcs.anl.gov] on behalf of
>>>>>>>>>>>>>> nek5000-users at lists.mcs.anl.gov
>>>>>>>>>>>>>> [nek5000-users at lists.mcs.anl.gov]
>>>>>>>>>>>>>> Sent: Saturday, January 18, 2014 12:17 PM
>>>>>>>>>>>>>> To: nek5000-users at lists.mcs.anl.gov
>>>>>>>>>>>>>> Subject: Re: [Nek5000-users] Pipe with expansion
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Dear Paul,
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> I tried many ways to map my straight pipe geometry but it
>>>>>>>>>>>>>> does not seem to work properly
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> I used something like
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> X = X + Z * tan ( alpha )
>>>>>>>>>>>>>> Y = Y + Z* tan (alpha )
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> even that dint work. could please help me with this
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Thank you
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Kamal.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> On Jan 17, 2014, at 2:24 PM, nek5000-users at lists.mcs.anl.gov
>>>>>>>>>>>>>> wrote:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Hi Paul,
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Thanks paul. I tried working with the diverging mesh
>>>>>>>>>>>>>>> modification.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> I tried to use this form of equation to modify the mesh
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> z = mx + b
>>>>>>>>>>>>>>> z = ny + c
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> x = ( z - b ) / m
>>>>>>>>>>>>>>> y = (z - c) / n
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Do you think would work ? or is there any other way to
>>>>>>>>>>>>>>> input that ?
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Thanks,
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Kamal
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> On 17/01/2014 14:14, nek5000-users at lists.mcs.anl.govwrote:
>>>>>>>>>>>>>>>> Kamal,
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> 1) To check for convergence, run your simulation for
>>>>>>>>>>>>>>>> increasing polynomial orders ( lx1 in the SIZE file) and
>>>>>>>>>>>>>>>> measure some consistent quantity (drag, TKE, etc). You
>>>>>>>>>>>>>>>> can plot this quantity against lx1 and this should give
>>>>>>>>>>>>>>>> you a good picture of how you are converging (without
>>>>>>>>>>>>>>>> needing to change the physical mesh).
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> 2) If you weren't using temperature in your simulation,
>>>>>>>>>>>>>>>> you could do put the following code snippet in your userchk
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> c-------------------------------------------
>>>>>>>>>>>>>>>> integer i, ntot
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> ntot = nx1*ny1*nz1*nelv ! total number of points in
>>>>>>>>>>>>>>>> simulation (on THIS processor)
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> do i = 1,ntot
>>>>>>>>>>>>>>>> t(i,1,1,1,1) = 0.5*(vx(i,1,1,1)**2 + vy(i,1,1,1)**2 +
>>>>>>>>>>>>>>>> vz(i,1,1,1)**2)
>>>>>>>>>>>>>>>> enddo
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> ifto = .true.
>>>>>>>>>>>>>>>> c-------------------------------------------
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> I've assumed here that your density is unity. This
>>>>>>>>>>>>>>>> computed kinetic energy point-wise and stores it in the
>>>>>>>>>>>>>>>> temperature field. The part "ifto = .true." tells Nek to
>>>>>>>>>>>>>>>> output the temperature field whenever it outputs a field
>>>>>>>>>>>>>>>> file. You could then view this in visit just like you
>>>>>>>>>>>>>>>> would the velocity field.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Hope this helps!
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Josh
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> On Wed, Jan 15, 2014 at 9:52 AM,
>>>>>>>>>>>>>>>> <nek5000-users at lists.mcs.anl.gov> wrote:
>>>>>>>>>>>>>>>> Hi Paul,
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> I will try that mapping, I created a straight pipe to do
>>>>>>>>>>>>>>>> some simulations.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> 1) Is there a way to check my spectral convergence, so
>>>>>>>>>>>>>>>> that I can do some mesh convergence study?
>>>>>>>>>>>>>>>> 2) Is there a way to plot the kinetic energy in the flow ?
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Thank you,
>>>>>>>>>>>>>>>> Kamal
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> On 15/01/2014 12:14, nek5000-users at lists.mcs.anl.gov wrote:
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Hi Kamal,
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> For the geometry you describe, I would apply mesh morphing
>>>>>>>>>>>>>>>> to a standard straight pipe. You can create such a pipe
>>>>>>>>>>>>>>>> using a subset of the mkmesh script provided in the expansion
>>>>>>>>>>>>>>>> example.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> If your transition region is conical, then I woud make
>>>>>>>>>>>>>>>> certain that the change in slope occurs at element
>>>>>>>>>>>>>>>> boundaries,
>>>>>>>>>>>>>>>> i.e., as in the half cross-section depicted below:
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> _______________
>>>>>>>>>>>>>>>> /| | |
>>>>>>>>>>>>>>>> / | | |
>>>>>>>>>>>>>>>> /| | | |
>>>>>>>>>>>>>>>> ________________/ | | | |
>>>>>>>>>>>>>>>> | | | | | | | |
>>>>>>>>>>>>>>>> | | | | | | | |
>>>>>>>>>>>>>>>> +-----+-----+---+--+---+------+------+----> z
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Paul
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> On Wed, 15 Jan 2014, nek5000-users at lists.mcs.anl.gov wrote:
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Hi Paul,
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> I looked at the example and it looks very helpful, but for
>>>>>>>>>>>>>>>> a sudden expansion we have only two parts (i.e) the inlet
>>>>>>>>>>>>>>>> pipe and the outlet pipe. Whereas in a diverging pipe we
>>>>>>>>>>>>>>>> have three section (i.e,) The inlet pipe, Diverging
>>>>>>>>>>>>>>>> section and the outlet pipe.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Is it possible for me to create a 2D diverging section
>>>>>>>>>>>>>>>> using mesh modification and revolve it around the centre
>>>>>>>>>>>>>>>> axis to get a 3d diverging pipe ?
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> or should I apply the mesh modification directly to the 3d
>>>>>>>>>>>>>>>> sudden expansion pipe using usrdat2() ?
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Thanks,
>>>>>>>>>>>>>>>> Kamal
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> On 14/01/2014 21:09, nek5000-users at lists.mcs.anl.gov wrote:
>>>>>>>>>>>>>>>> Hi Paul,
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Thanks a lot for the update. I will take a look at as soon
>>>>>>>>>>>>>>>> as possible and keep you updated with it.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Thank you,
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Kamal
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> On Jan 14, 2014, at 9:04 PM,
>>>>>>>>>>>>>>>> nek5000-users at lists.mcs.anl.gov wrote:
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Kamal,
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> I've added an example for a step-type expansion in a pipe.
>>>>>>>>>>>>>>>> New example directory
>>>>>>>>>>>>>>>> is nek5_svn/examples/expansion, with a README.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> If you want a standard diffuser, I would use
>>>>>>>>>>>>>>>> mesh-morphing, as outlined in the
>>>>>>>>>>>>>>>> nek primer, which can be found on this page:
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> http://nek5000.mcs.anl.gov/index.php/UG#Documentation
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> I've also automated our turbulent outflow bc treatment --
>>>>>>>>>>>>>>>> one simply provides an
>>>>>>>>>>>>>>>> expansion factor (typically ~ 1.5) and two persistent
>>>>>>>>>>>>>>>> arrays to turb_outflow(), which
>>>>>>>>>>>>>>>> is now in navier5.f. This can be useful when very
>>>>>>>>>>>>>>>> strong vortices are leaving the
>>>>>>>>>>>>>>>> domain, which is possible for certain diffuser flow
>>>>>>>>>>>>>>>> conditions (and others).
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Paul
>>>>>>>>>>>>>>>> ________________________________________
>>>>>>>>>>>>>>>> From: nek5000-users-bounces at lists.mcs.anl.gov
>>>>>>>>>>>>>>>> [nek5000-users-bounces at lists.mcs.anl.gov] on behalf
>>>>>>>>>>>>>>>> ofnek5000-users at lists.mcs.anl.gov
>>>>>>>>>>>>>>>> [nek5000-users at lists.mcs.anl.gov]
>>>>>>>>>>>>>>>> Sent: Monday, January 13, 2014 3:35 AM
>>>>>>>>>>>>>>>> To: nek5000-users at lists.mcs.anl.gov
>>>>>>>>>>>>>>>> Subject: [Nek5000-users] Creating a Mesh
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Hi
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Can some one please help me in this because I am new to nek
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> 1) How can I create a .rea for a specific geometry say ' A
>>>>>>>>>>>>>>>> sudden
>>>>>>>>>>>>>>>> expansion pipe ' or a ' Diverging pipe '
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> 2) What tool I should use to create that mesh.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Thank you
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> kamal
>>>>>>>>>>>>>>>> _______________________________________________
>>>>>>>>>>>>>>>> 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
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>>>>>>>>>>>>>>>> _______________________________________________
>>>>>>>>>>>>>>>> Nek5000-users mailing list
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>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> _______________________________________________
>>>>>>>>>>>>>>>> Nek5000-users mailing list
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>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> _______________________________________________
>>>>>>>>>>>>>>>> Nek5000-users mailing list
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>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> _______________________________________________
>>>>>>>>>>>>>>>> Nek5000-users mailing list
>>>>>>>>>>>>>>>> Nek5000-users at lists.mcs.anl.gov
>>>>>>>>>>>>>>>> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> --
>>>>>>>>>>>>>>>> Josh Camp
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> "All that is necessary for the triumph of evil is that
>>>>>>>>>>>>>>>> good men do nothing" -- Edmund Burke
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> _______________________________________________
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>
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On Fri, 24 Jan 2014, nek5000-users at lists.mcs.anl.gov wrote:
> Hello Paul,
>
> Thanks for your reply. I am looking into the .usr file for defining the
> set_obj ().
>
> 1) Could you please tell me what is 'Enter the number of levels ?' in n2to3
>
> is it the number of elements in Z direction ?
>
> 2) As you said about storing the computed vorticity in velocity field to view
> in VisIT, I found the routine to compute the vorticity but I am stuck about
> adding it to the velocity filed to VisIT ? could you please tell me how it
> works or any example which stores vorticity to the .fld file as a separate
> variable.
>
>
> Thank you
>
> Kamal
>
>
> On 22/01/2014 16:53, nek5000-users at lists.mcs.anl.gov wrote:
>> Axial viscous stress is given by torq_calc -- that's no problem whatsoever.
>> You get a number as a
>> function of time.
>>
>> You can even get stresses on multiple subsets of the geometry (e.g., if you
>> had multiple branches
>> in the domain or multiple cylinders. The drag, which is a byproduct of
>> the torque computation (which
>> you can ignore), is given in terms of the viscous and pressure components
>> separately and as the
>> sum of the two.
>>
>> You can identify domain boundaries by checking the boundary conditions.
>> Here, I recommend
>> looking at the set_obj routines in several of the /example cases.
>>
>>
>> ________________________________________
>> From: nek5000-users-bounces at lists.mcs.anl.gov
>> [nek5000-users-bounces at lists.mcs.anl.gov] on behalf of
>> nek5000-users at lists.mcs.anl.gov [nek5000-users at lists.mcs.anl.gov]
>> Sent: Wednesday, January 22, 2014 9:37 AM
>> To: nek5000-users at lists.mcs.anl.gov
>> Subject: Re: [Nek5000-users] Pipe with expansion
>>
>> Hello Paul
>>
>> I was thinking about taking the tangential velocity near to the wall so
>> that I can figure out my length of the recirculation region.
>>
>> Is it possible for me to access the boundary elements of the mesh ??? so
>> that I can take the boundary element and then obtain the velocity at that
>> point so that I can figure out the length of my recirculation region.
>>
>> or take the *.fld file and read it to plot the datas I need.
>>
>>
>> I also want to calculate the axial viscous force acting on the entire pipe.
>>
>> which is given by
>>
>> C_v = F^v / ( d^2 * rho * U^2 ) = double integral ( 1/Re * (du / dr) )
>> dtheta dz
>>
>>
>> On Jan 22, 2014, at 4:07 PM, nek5000-users at lists.mcs.anl.gov wrote:
>>
>>> Hi Kamal,
>>>
>>> As I thought about it some more, if you're interested in the local wall
>>> shear stress
>>> magnitude I'm quite certain you can get this by plotting the magnitude of
>>> vorticity
>>> on the surface in question. (Note that the sign of the WSS, which in
>>> fact is a tensor
>>> or a vector when restricted to a given surface, is lost in this process,
>>> but that might
>>> not be relevant for your needs.) If that works, then you can readily
>>> compute the
>>> vorticity using one of the routines in nek and store the result in a
>>> velocity field, then
>>> view that field with VisIt. Of course WSS will require multiplication by
>>> viscosity.
>>>
>>> hth,
>>>
>>> Paul
>>>
>>> ________________________________________
>>> From: nek5000-users-bounces at lists.mcs.anl.gov
>>> [nek5000-users-bounces at lists.mcs.anl.gov] on behalf of
>>> nek5000-users at lists.mcs.anl.gov [nek5000-users at lists.mcs.anl.gov]
>>> Sent: Tuesday, January 21, 2014 10:33 AM
>>> To: nek5000-users at lists.mcs.anl.gov
>>> Subject: Re: [Nek5000-users] Pipe with expansion
>>>
>>> Hi paul,
>>>
>>> can I make this to be drag or shear quantities to be return to the a
>>> separate file so that it will easy for me to plot.
>>>
>>> By the way it gives the integral quantity. Think for example I need to
>>> find the shear stress on the wall from the inlet to outlet at a
>>> particular time = 2 . How can I do that ?
>>>
>>> Is there way to find the number of elements in x,y and z direction ?
>>>
>>> On 21/01/2014 17:32, nek5000-users at lists.mcs.anl.gov wrote:
>>>> Hi Kamal,
>>>>
>>>> Your integrated drag quantities should be written to the logfile
>>>> (stdout),
>>>> assuming you've set the arguments in the call to be .true.
>>>>
>>>> Paul
>>>>
>>>> On Tue, 21 Jan 2014, nek5000-users at lists.mcs.anl.gov wrote:
>>>>
>>>>> Hi Paul,
>>>>>
>>>>> I checked the set_obj subroutine and implemented one in my .USR file.
>>>>> The code seem to run without any errors but I don't find where these
>>>>> variables are getting stored.
>>>>>
>>>>> I use VisIT to visualize my output, even there was no change in it.
>>>>>
>>>>> do I have to define my own output file and write the variables out ?
>>>>>
>>>>> Thanks,
>>>>>
>>>>> Kamal.
>>>>>
>>>>>
>>>>> On 20/01/2014 21:52, nek5000-users at lists.mcs.anl.gov wrote:
>>>>>> Hi Kamal,
>>>>>>
>>>>>> You'll need to compute your own tke by manipulating the
>>>>>> velocity fields.
>>>>>>
>>>>>> You can get running averages of the requisite quantities
>>>>>> via calls to "avg_all" which is found in navier5.f
>>>>>>
>>>>>> You can compute shear stress on the wall simply by computing
>>>>>> the drag on the wall, which can be done via a call to torque_calc(),
>>>>>> also found in navier5.f
>>>>>>
>>>>>> If you cd to /examples and type:
>>>>>>
>>>>>> grep torq */*.usr
>>>>>>
>>>>>> you'll find many examples of calls to torque_calc. You simply
>>>>>> need to prescribe the surfaces on which shear is to be integrated.
>>>>>>
>>>>>> I typically write a routine "set_obj" to identify such surfaces
>>>>>> on the first call to usrchk.
>>>>>>
>>>>>> grep set_obj */*.usr
>>>>>>
>>>>>> will show similar examples.
>>>>>>
>>>>>> I would recommend trying this for laminar Poiseiulle flow in
>>>>>> a very simple channel just to check that your calls are properly
>>>>>> set.
>>>>>>
>>>>>> Best,
>>>>>>
>>>>>> Paul
>>>>>>
>>>>>>
>>>>>> On Mon, 20 Jan 2014, nek5000-users at lists.mcs.anl.gov wrote:
>>>>>>
>>>>>>> Hi Paul,
>>>>>>>
>>>>>>> Thanks and that helped.
>>>>>>>
>>>>>>> Where can I find the variables like Turbulent KE , shear stress on
>>>>>>> the wall. ?
>>>>>>>
>>>>>>> Do i have to activate some parameters for calculating them ?
>>>>>>>
>>>>>>> If I had to plot them.
>>>>>>>
>>>>>>> Thanks,
>>>>>>> Kamal
>>>>>>>
>>>>>>>
>>>>>>> On Jan 20, 2014, at 5:41 AM, nek5000-users at lists.mcs.anl.gov wrote:
>>>>>>>
>>>>>>>> Kamal,
>>>>>>>>
>>>>>>>> Looks good.
>>>>>>>>
>>>>>>>> I'm guessing that one further refinement would be:
>>>>>>>>
>>>>>>>> if (z.gt.z0) scale = 1 + (smax-1)*(z-z0)/(z1-z0)
>>>>>>>> if (z.gt.z1) scale = smax
>>>>>>>>
>>>>>>>> which would yield
>>>>>>>>
>>>>>>>> scale = 1 when z=z0
>>>>>>>> scale = smax when z >= z1
>>>>>>>>
>>>>>>>> Paul
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> On Sun, 19 Jan 2014, nek5000-users at lists.mcs.anl.gov wrote:
>>>>>>>>
>>>>>>>>> Hi paul,
>>>>>>>>>
>>>>>>>>> The code works fine, but there should be a small change thats has
>>>>>>>>> to be done
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> if (z.gt.z0) scale = 1 + (z /(z1-z0 )))
>>>>>>>>> if (z.gt.z1) scale = smax
>>>>>>>>>
>>>>>>>>> This creates a perfect diverging pipe.
>>>>>>>>>
>>>>>>>>> Thanks for the help paul.
>>>>>>>>>
>>>>>>>>> Kamal
>>>>>>>>>
>>>>>>>>> On Jan 20, 2014, at 12:09 AM, nek5000-users at lists.mcs.anl.gov wrote:
>>>>>>>>>
>>>>>>>>>> Hi paul,
>>>>>>>>>>
>>>>>>>>>> If I am not wrong,
>>>>>>>>>> I make a mesh with three straight pipes( inlet, divergent,
>>>>>>>>>> outlet ) connected together via n2to3 so that I know the element
>>>>>>>>>> connectivity places of the divergent section (z0,z1) and use the
>>>>>>>>>> section what you gave
>>>>>>>>>>
>>>>>>>>>> Thank you for the code
>>>>>>>>>>
>>>>>>>>>> Kamal
>>>>>>>>>>
>>>>>>>>>> On Jan 19, 2014, at 8:45 PM, nek5000-users at lists.mcs.anl.gov wrote:
>>>>>>>>>>
>>>>>>>>>>> Kamal,
>>>>>>>>>>>
>>>>>>>>>>> I would do the following in usrdat2():
>>>>>>>>>>>
>>>>>>>>>>> n=nx1*ny1*nz1*nelt
>>>>>>>>>>>
>>>>>>>>>>> do i=1,n
>>>>>>>>>>> x=xm1(i,1,1,1)
>>>>>>>>>>> y=ym1(i,1,1,1)
>>>>>>>>>>> z=ym1(i,1,1,1)
>>>>>>>>>>> scale = 1.
>>>>>>>>>>> if (z.gt.z0) scale = smax*(z-z0/(z1-z0)
>>>>>>>>>>> if (z.gt.z1) scale = smax
>>>>>>>>>>> xm1(i,1,1,1) = scale*x
>>>>>>>>>>> ym1(i,1,1,1) = scale*y
>>>>>>>>>>> enddo
>>>>>>>>>>>
>>>>>>>>>>> Paul
>>>>>>>>>>>
>>>>>>>>>>> Make certain that z1 and z0 correspond to z values
>>>>>>>>>>> that precisely coincide with element interfaces.
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> On Sun, 19 Jan 2014, nek5000-users at lists.mcs.anl.gov wrote:
>>>>>>>>>>>
>>>>>>>>>>>> Hi Paul,
>>>>>>>>>>>>
>>>>>>>>>>>> I looked into the Peris example but It is so what same like
>>>>>>>>>>>> the stenosis example with a Cosine deformation.
>>>>>>>>>>>>
>>>>>>>>>>>> In my case it is a pipe with conical divergent. I tried to
>>>>>>>>>>>> play around the variables Xm1, Ym1 and Zm1 but the mapping
>>>>>>>>>>>> doesn't go well.
>>>>>>>>>>>>
>>>>>>>>>>>> Could you please help me with this.
>>>>>>>>>>>>
>>>>>>>>>>>> Thank you,
>>>>>>>>>>>>
>>>>>>>>>>>> Kamal
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> On Jan 18, 2014, at 7:26 PM, nek5000-users at lists.mcs.anl.gov
>>>>>>>>>>>> wrote:
>>>>>>>>>>>>
>>>>>>>>>>>>> Hi Paul,
>>>>>>>>>>>>>
>>>>>>>>>>>>> I looked at the Helix and stenosis example but they are using
>>>>>>>>>>>>> cosine functions to deform
>>>>>>>>>>>>>
>>>>>>>>>>>>> I tried to use a tangent function but it bends the whole pipe.
>>>>>>>>>>>>>
>>>>>>>>>>>>> I dint look at peris example .
>>>>>>>>>>>>>
>>>>>>>>>>>>> I will take a look at it and let you know.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Thank you
>>>>>>>>>>>>>
>>>>>>>>>>>>> Kamal
>>>>>>>>>>>>>
>>>>>>>>>>>>> On Jan 18, 2014, at 7:22 PM, nek5000-users at lists.mcs.anl.gov
>>>>>>>>>>>>> wrote:
>>>>>>>>>>>>>
>>>>>>>>>>>>>> Kamal,
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Have you looked at the peris example? The usr file there
>>>>>>>>>>>>>> shows how to deform
>>>>>>>>>>>>>> a pipe geometry.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Paul
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> From: nek5000-users-bounces at lists.mcs.anl.gov
>>>>>>>>>>>>>> [nek5000-users-bounces at lists.mcs.anl.gov] on behalf of
>>>>>>>>>>>>>> nek5000-users at lists.mcs.anl.gov
>>>>>>>>>>>>>> [nek5000-users at lists.mcs.anl.gov]
>>>>>>>>>>>>>> Sent: Saturday, January 18, 2014 12:17 PM
>>>>>>>>>>>>>> To: nek5000-users at lists.mcs.anl.gov
>>>>>>>>>>>>>> Subject: Re: [Nek5000-users] Pipe with expansion
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Dear Paul,
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> I tried many ways to map my straight pipe geometry but it
>>>>>>>>>>>>>> does not seem to work properly
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> I used something like
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> X = X + Z * tan ( alpha )
>>>>>>>>>>>>>> Y = Y + Z* tan (alpha )
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> even that dint work. could please help me with this
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Thank you
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Kamal.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> On Jan 17, 2014, at 2:24 PM, nek5000-users at lists.mcs.anl.gov
>>>>>>>>>>>>>> wrote:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Hi Paul,
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Thanks paul. I tried working with the diverging mesh
>>>>>>>>>>>>>>> modification.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> I tried to use this form of equation to modify the mesh
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> z = mx + b
>>>>>>>>>>>>>>> z = ny + c
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> x = ( z - b ) / m
>>>>>>>>>>>>>>> y = (z - c) / n
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Do you think would work ? or is there any other way to
>>>>>>>>>>>>>>> input that ?
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Thanks,
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Kamal
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> On 17/01/2014 14:14, nek5000-users at lists.mcs.anl.govwrote:
>>>>>>>>>>>>>>>> Kamal,
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> 1) To check for convergence, run your simulation for
>>>>>>>>>>>>>>>> increasing polynomial orders ( lx1 in the SIZE file) and
>>>>>>>>>>>>>>>> measure some consistent quantity (drag, TKE, etc). You
>>>>>>>>>>>>>>>> can plot this quantity against lx1 and this should give
>>>>>>>>>>>>>>>> you a good picture of how you are converging (without
>>>>>>>>>>>>>>>> needing to change the physical mesh).
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> 2) If you weren't using temperature in your simulation,
>>>>>>>>>>>>>>>> you could do put the following code snippet in your userchk
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> c-------------------------------------------
>>>>>>>>>>>>>>>> integer i, ntot
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> ntot = nx1*ny1*nz1*nelv ! total number of points in
>>>>>>>>>>>>>>>> simulation (on THIS processor)
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> do i = 1,ntot
>>>>>>>>>>>>>>>> t(i,1,1,1,1) = 0.5*(vx(i,1,1,1)**2 + vy(i,1,1,1)**2 +
>>>>>>>>>>>>>>>> vz(i,1,1,1)**2)
>>>>>>>>>>>>>>>> enddo
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> ifto = .true.
>>>>>>>>>>>>>>>> c-------------------------------------------
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> I've assumed here that your density is unity. This
>>>>>>>>>>>>>>>> computed kinetic energy point-wise and stores it in the
>>>>>>>>>>>>>>>> temperature field. The part "ifto = .true." tells Nek to
>>>>>>>>>>>>>>>> output the temperature field whenever it outputs a field
>>>>>>>>>>>>>>>> file. You could then view this in visit just like you
>>>>>>>>>>>>>>>> would the velocity field.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Hope this helps!
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Josh
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> On Wed, Jan 15, 2014 at 9:52 AM,
>>>>>>>>>>>>>>>> <nek5000-users at lists.mcs.anl.gov> wrote:
>>>>>>>>>>>>>>>> Hi Paul,
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> I will try that mapping, I created a straight pipe to do
>>>>>>>>>>>>>>>> some simulations.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> 1) Is there a way to check my spectral convergence, so
>>>>>>>>>>>>>>>> that I can do some mesh convergence study?
>>>>>>>>>>>>>>>> 2) Is there a way to plot the kinetic energy in the flow ?
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Thank you,
>>>>>>>>>>>>>>>> Kamal
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> On 15/01/2014 12:14, nek5000-users at lists.mcs.anl.gov wrote:
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Hi Kamal,
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> For the geometry you describe, I would apply mesh morphing
>>>>>>>>>>>>>>>> to a standard straight pipe. You can create such a pipe
>>>>>>>>>>>>>>>> using a subset of the mkmesh script provided in the expansion
>>>>>>>>>>>>>>>> example.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> If your transition region is conical, then I woud make
>>>>>>>>>>>>>>>> certain that the change in slope occurs at element
>>>>>>>>>>>>>>>> boundaries,
>>>>>>>>>>>>>>>> i.e., as in the half cross-section depicted below:
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> _______________
>>>>>>>>>>>>>>>> /| | |
>>>>>>>>>>>>>>>> / | | |
>>>>>>>>>>>>>>>> /| | | |
>>>>>>>>>>>>>>>> ________________/ | | | |
>>>>>>>>>>>>>>>> | | | | | | | |
>>>>>>>>>>>>>>>> | | | | | | | |
>>>>>>>>>>>>>>>> +-----+-----+---+--+---+------+------+----> z
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Paul
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> On Wed, 15 Jan 2014, nek5000-users at lists.mcs.anl.gov wrote:
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Hi Paul,
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> I looked at the example and it looks very helpful, but for
>>>>>>>>>>>>>>>> a sudden expansion we have only two parts (i.e) the inlet
>>>>>>>>>>>>>>>> pipe and the outlet pipe. Whereas in a diverging pipe we
>>>>>>>>>>>>>>>> have three section (i.e,) The inlet pipe, Diverging
>>>>>>>>>>>>>>>> section and the outlet pipe.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Is it possible for me to create a 2D diverging section
>>>>>>>>>>>>>>>> using mesh modification and revolve it around the centre
>>>>>>>>>>>>>>>> axis to get a 3d diverging pipe ?
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> or should I apply the mesh modification directly to the 3d
>>>>>>>>>>>>>>>> sudden expansion pipe using usrdat2() ?
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Thanks,
>>>>>>>>>>>>>>>> Kamal
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> On 14/01/2014 21:09, nek5000-users at lists.mcs.anl.gov wrote:
>>>>>>>>>>>>>>>> Hi Paul,
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Thanks a lot for the update. I will take a look at as soon
>>>>>>>>>>>>>>>> as possible and keep you updated with it.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Thank you,
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Kamal
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> On Jan 14, 2014, at 9:04 PM,
>>>>>>>>>>>>>>>> nek5000-users at lists.mcs.anl.gov wrote:
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Kamal,
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> I've added an example for a step-type expansion in a pipe.
>>>>>>>>>>>>>>>> New example directory
>>>>>>>>>>>>>>>> is nek5_svn/examples/expansion, with a README.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> If you want a standard diffuser, I would use
>>>>>>>>>>>>>>>> mesh-morphing, as outlined in the
>>>>>>>>>>>>>>>> nek primer, which can be found on this page:
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> http://nek5000.mcs.anl.gov/index.php/UG#Documentation
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> I've also automated our turbulent outflow bc treatment --
>>>>>>>>>>>>>>>> one simply provides an
>>>>>>>>>>>>>>>> expansion factor (typically ~ 1.5) and two persistent
>>>>>>>>>>>>>>>> arrays to turb_outflow(), which
>>>>>>>>>>>>>>>> is now in navier5.f. This can be useful when very
>>>>>>>>>>>>>>>> strong vortices are leaving the
>>>>>>>>>>>>>>>> domain, which is possible for certain diffuser flow
>>>>>>>>>>>>>>>> conditions (and others).
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Paul
>>>>>>>>>>>>>>>> ________________________________________
>>>>>>>>>>>>>>>> From: nek5000-users-bounces at lists.mcs.anl.gov
>>>>>>>>>>>>>>>> [nek5000-users-bounces at lists.mcs.anl.gov] on behalf
>>>>>>>>>>>>>>>> ofnek5000-users at lists.mcs.anl.gov
>>>>>>>>>>>>>>>> [nek5000-users at lists.mcs.anl.gov]
>>>>>>>>>>>>>>>> Sent: Monday, January 13, 2014 3:35 AM
>>>>>>>>>>>>>>>> To: nek5000-users at lists.mcs.anl.gov
>>>>>>>>>>>>>>>> Subject: [Nek5000-users] Creating a Mesh
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Hi
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Can some one please help me in this because I am new to nek
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> 1) How can I create a .rea for a specific geometry say ' A
>>>>>>>>>>>>>>>> sudden
>>>>>>>>>>>>>>>> expansion pipe ' or a ' Diverging pipe '
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> 2) What tool I should use to create that mesh.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Thank you
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> kamal
>>>>>>>>>>>>>>>> _______________________________________________
>>>>>>>>>>>>>>>> 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
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> _______________________________________________
>>>>>>>>>>>>>>>> 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
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> --
>>>>>>>>>>>>>>>> Josh Camp
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> "All that is necessary for the triumph of evil is that
>>>>>>>>>>>>>>>> good men do nothing" -- Edmund Burke
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> _______________________________________________
>>>>>>>>>>>>>>>> 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
>>>>>>>>>>>>>> _______________________________________________
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>>>>>>>>>>>>>> Nek5000-users at lists.mcs.anl.gov
>>>>>>>>>>>>>> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
>>>>>>>>>>>>> _______________________________________________
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>>>>>>>>>>>>> Nek5000-users at lists.mcs.anl.gov
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>>>>>>>>>>>>
>>>>>>>>>>> _______________________________________________
>>>>>>>>>>> Nek5000-users mailing list
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