Reply To: Convergence varying radial velocity and timestep size in a simulation

[Murari Iyengar]

That is normal for transient cases. The residuals will shoot up at the start of a new timestep and decrease as the iterations carry on. You need to look at the final value of the residual at the end of a timestep to see if the solution is converging. 1e-13 is very good convergence for continuity indicating a fully converged flow solution. The downside to having CFL<<1 is that your simulation will take longer to complete/use more resources than required to reach the intended flow time.