Fix constant timestep with explicit TIME_STEPPING simulations, is it possible?

ssss · February 2, 2018, 03:05

Hi,

I am trying to run explicit simulations in SU2 using UNSTEADY_SIMULATION= TIME_STEPPING and EULER_EXPLICIT time scheme. However, I am not able of setting a constant timestep. I know how to impose constant dt with dual time stepping simulations, but I cannot find a way to impose the same constant time step with the normal time stepping method. I have tried using MAX_DELTA_DT together with a high CFL number but this doesn't work.

I would mind using a constant CFL in my simulations, the problem is that there is no way of obtaining the physical time from the surface_flow*.csv and history.vtk files, any idea on how to obtain the physical time of the output files given by SU2?

Thank you

fpalacios · February 24, 2018, 12:36

Have you try with

% Unsteady simulation (NO, TIME_STEPPING, DUAL_TIME_STEPPING-1ST_ORDER,
% DUAL_TIME_STEPPING-2ND_ORDER, HARMONIC_BALANCE)
UNSTEADY_SIMULATION= TIME_STEPPING

and the options in UNSTEADY SIMULATION section?

Best,
Francisco

If that doesn't work... I think it would be a good idea to take a look at the source code. What you are proposing is a reasonable capability that should be in SU2.

Best,
Francisco

February 2, 2018, 03:05	Fix constant timestep with explicit TIME_STEPPING simulations, is it possible?	#1
ssss Senior Member anonymous Join Date: Aug 2014 Posts: 205 Rep Power: 12	Hi, I am trying to run explicit simulations in SU2 using UNSTEADY_SIMULATION= TIME_STEPPING and EULER_EXPLICIT time scheme. However, I am not able of setting a constant timestep. I know how to impose constant dt with dual time stepping simulations, but I cannot find a way to impose the same constant time step with the normal time stepping method. I have tried using MAX_DELTA_DT together with a high CFL number but this doesn't work. I would mind using a constant CFL in my simulations, the problem is that there is no way of obtaining the physical time from the surface_flow*.csv and history.vtk files, any idea on how to obtain the physical time of the output files given by SU2? Thank you

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February 24, 2018, 12:36		#2
fpalacios Super Moderator Francisco Palacios Join Date: Jan 2013 Location: Long Beach, CA Posts: 404 Rep Power: 15	Have you try with % Unsteady simulation (NO, TIME_STEPPING, DUAL_TIME_STEPPING-1ST_ORDER, % DUAL_TIME_STEPPING-2ND_ORDER, HARMONIC_BALANCE) UNSTEADY_SIMULATION= TIME_STEPPING and the options in UNSTEADY SIMULATION section? Best, Francisco If that doesn't work... I think it would be a good idea to take a look at the source code. What you are proposing is a reasonable capability that should be in SU2. Best, Francisco