Learning Forum

[Milne Ando]

G'day,

I've tried several different settings to find a optimal scheme for 3D VIV simulations. Basicly, I'll keep using PISO since it's highly recommended for transient flow. (and with Green-Gauss Node Based gradient). But what about pressure interpolation(PRESTO!, body force weighted) and under-relaxation factors for pressure and momentum? I tried both pressure interpolation schemes, but didn't benefit from them as the pic shows:

"equations converged but mesh motion hasn't reached convergence criterion (1e-05)."

Does anyone know how to make this kind of simulation stable? Please share with me. Thank you!

Note that my mesh was built well with minimum orthogonal quality of 0.3.

[Federico Alzamora Previtali]

Check if reducing the time step helps with convergence of the mesh motion.