[mecbe2002]

Hi all,

I want to simulate steady inviscid supersonic compressible flow problem.
In OF1.6 no solver is available for the above problem.
"rhoSonicFoam" a density based solver for inviscid transient flows, so speed up the convergence for steady state problems, local time stepping is a good approach.

If someone have implemented the local time stepping, it can be posted in the forum or someone can given an idea to implement the local time stepping

thanks
mecbe

[roth]

You might try CoEuler which adjusts the local timestep to maintain Courant below a specified level to accelerate convergence to steady state:

ddtSchemes
{
//    default backward;
    default CoEuler phi maxCo 0.5; 
}

Mike

[mecbe2002]

Hi Mike,

I tried the CoEuler ddt scheme.

But i have one question.
CoEuler maintains the local Courant number to the specified value, so how to decide the time step value, that to be specified in controlDict file.

say for eg. i set ddt scheme as CoEuler phi maxCo 0.8;

minimum mesh size - 2e-3m, velocity U - 858 m/s, velocity of sound c - 343 m/s,

so for Courant No - 1, Global deltaT = 1.6653e-6.

So what time step value to specify in the controlDict file for the above condition.

thanks
mecbe