Hi I was wondering if anybody know a way to estimate how many inner iterations i need to use in an unsteady flow problem using NUMECA Solver and if its possible to estimate a reduction to the inner iterations number according to the residual diagram.

Dimitri,

The number of inner iterations required depends on the physical time step. If you use a very small physical time step compared to the characteristic time scale of your problem (for example the period), then you might only need bout 20 to 30 inner iterations per time step. If you double the physical time step then your might need to double also the number of inner iterations to reach the same convergence level.

Usually we observe that, at each physical time step, a convergence of about 1 to 2 orders of magnitude is necessary and sufficient to trust the solution.

If you need any additional help, do not hesitate to contact us at support@numeca.be

Bruno