[jignesh_thaker2007]

i am trying to solve the two phase simulation of hose pipe which is located at sea so its shape becomes like wave. and continuously water and air are flow inside the one end of the pipe and the other hand is fixed.
pipe is moving like wave so when the inlet end of the pipe is going above then air is come inside the pipe and when it comes down then water come inside the pipe.
i got the simulation of moving mesh and also got the simulation of air and water inside the pipe with interDyMFoam. but it is for same velocity of air and water.
But now i have trouble in how to give the different velocity of air and water? so plz help me.
i m still waiting for ur reply.
thank you very much.

[Nilesh_87]

Hello Sir,
I am solving 2D external aerodynamic case of simple ahmed car profile. I am using pisoFoam. deltat is 0.001. but i am getting very high courant number. I assumed Co. no. as 1 and fixed deltat. Can you please help me?

Thanks & regards
Nilesh

[jignesh_thaker2007]

Originally Posted by Nilesh_87

Hello Sir,
I am solving 2D external aerodynamic case of simple ahmed car profile. I am using pisoFoam. deltat is 0.001. but i am getting very high courant number. I assumed Co. no. as 1 and fixed deltat. Can you please help me?

Thanks & regards
Nilesh

i am happy to see that you are using openFOAM. now for your problem first u see the openFoam tutorials of lid driven cavity in that tutorial u will find your answer because in that u will find the courant number condition and its definition,

if u unable to find that then replied me ok
best wishes

Jignesh

[musahossein]

Originally Posted by Nilesh_87

Hello Sir,
I am solving 2D external aerodynamic case of simple ahmed car profile. I am using pisoFoam. deltat is 0.001. but i am getting very high courant number. I assumed Co. no. as 1 and fixed deltat. Can you please help me?

Thanks & regards
Nilesh

Courant number of 1 is very high, and can lead to instability when you have fine mesh or your computations require many iterations. As suggested in another post, please review the lid driven cavity example and try with the courant number there. Once you have decided on a Courant number you can determine the appropriate deltaT based on your cell size. This is also explained in the referenced example.