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HiFiLES / HiFiLES-solver

High Fidelity Large Eddy Simulation Solver
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Simulation of Jet flow #132

Closed sumit-sp closed 7 years ago

sumit-sp commented 7 years ago

I am trying to do simulation for jet flow but I am getting following error.

Iter Res[Rho] Res[RhoVelx] Res[RhoVely] Res[RhoE] Fx_Total Fy_Total 30000 0.00096002 0.00236180 0.00064232 0.01007507 -nan -nan Writing Tecplot file number 30000 on rank 0

In calculation of plot_quantitiy mach: Fatal error 'NaN' at ../src/eles.cpp:4525

Primary job terminated normally, but 1 process returned a non-zero exit code.. Per user-direction, the job has been aborted.

I am attaching input file and an image that shows how I have chosen boundary conditions. Please help if I'm doing something wrong. untitled input_flatplate_a.docx

mlopez14 commented 7 years ago

Thanks for the detailed graph and the input file! In the input file I see you're selecting a case with Re = 1e5 and Ma = 0.5. Because the initial flow is uniform, there will be a strong initial "vacuum" forming at the "adiabat_fix" walls. It's as if the fluid were traveling at Ma = 0.5 and suddenly a wall appeared.

I would recommend starting with very mild initial conditions to make the initial appearance of the wall less sudden. More explicitly, set Re = 100, Ma = 0.01, p = 2

If this setup doesn't work, set p = 1. If the simulation runs, save the restart file, increase the Re and Ma values and restart.

Also, the "sub_out_simp" boundary conditions will be trying to keep the fluid moving at the specified Re and Ma values. I would suggest setting those three boundaries to either "adiabat_fix" or "slip_wall". To prevent pressurizing your domain too much, place the boundaries far away from the jet.

Let us know how it goes!

sumit-sp commented 7 years ago

this may be a stupid question, but what is p? is it pressure I mean in the input tutorial there is no such thing. and one more question how to set required ambient/far field conditions.