[Leonardo.flores]

Hello,

I am performing a mesh independence of a 2d Cylinder, kw SST model, Reynolds related to cylinder= 1.4e5 and Y+=0.9. And have this problem when increase iterations per time step, from 20 ( suggested by fluent) to 50, 70 or 100 my results change dramatically.
iterations per ts.png

My CourantFL is 0.3, and time step = 0.0001.

Solution methods are: PISO, Pressure PRESTO!, momentum, turbulent kinetic energy and specific dissipation rate are 2d Order upwind. And Transient formulation Second Order Implicit.


The problem I think is the continuity residuals... they stay very high.... and solution doesnt converge in every timestep because of it.

I say high because some papers consider converged when reach 1e-6... and I am getting 1e-4 with 100 iterations!

residuals.png

What would you do? Thank you for reading.