[hitzhwan]

For the CFD, Which should be done first for grid independence or time step independence?

I met a problem, when I increased the mesh number, the CFD process may sometimes diverge for sometimes, what should I do? Can I use the adaptive timestep to solve the problem?

[LuckyTran]

It's like asking if you need to open your left eye first or your right eye first when you wake up. You're not awake until both eyes are open. Or whether you step forward with your left foot or your right foot when you walk.

You need to do both.

[hitzhwan]

Originally Posted by LuckyTran

It's like asking if you need to open your left eye first or your right eye first when you wake up. You're not awake until both eyes are open. Or whether you step forward with your left foot or your right foot when you walk.

You need to do both.

Maybe you do not understand my question. As you know, when I increase the mesh number, the timestep also needs to decrease to ensure the Courant number<1, so it is impossible to acquire a fixed timestep.