[Nek5000-users] Update on axisymmetric jet problem

[nek5000-users at lists.mcs.anl.gov]

Dear Nek users,

Just to give some more information on the problem I mentioned some days 
ago (down below is the original message), here is some more data:

- One of the boundary conditions is periodically oscillating velocity.

- If I remove the axisymmetric conditions, that being:

    · IFHEAT F
    · IFAXIS F
    · IFAZIV F

and simply run it as a 2D example, it seems to run just fine.

- Extremely high values of artificial viscosity (1.0000000E+00     p103) 
will make it run longer, but it ends up crashing as well.

- Even when it runs for some seconds (before crashing), log file keeps 
giving this kind of error messages:

     19565   100 **ERROR**: Failed in HMHOLTZ: PRES   6.2650E+00   
8.4054E+01   1.0000E-06

Any advice will be greatly appreciated.

Thank you in advance.

MViturro


--------Original message---------------

Dear Nek users,

I am doing my master thesis at Technical University of Madrid and I am
using Nek5000 to study an axisymmetric jet.

I have generated the mesh using genbox. Then I have try to run numerical
simulations:

1) 2D
2) Setting: IFAXIS T
3) Setting: IFAXIS T, IFAZIV T (and with IFHEAT T, to plot the azimuthal
velocity.

In all cases my simulation crashes, due to some problems in the boundary
(I have tried with both ON and O BC)

So, I have added artificial viscosity, but the axysimmetric simulation
(case2 2 and 3)  still  crashes:


        3.000000         p99    dealiasing:if <0 disable
        0.0000000E+00     p100 reserved
        1.0000000E+00     p101   No. of additional filter modes
        0.0000000E+00
        1.0000000E-02     p103   weight of stabilizing filter (.01)




Could you give me any recommendation to follow?

Thank you in advance.

MViturro


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