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Cairol July 27, 2006 04:50

Oscillating Residuals
Hi all

I'm calculating a flow arround a Turbofans nacelle with mixing of core and bypass massflow using a 6 million nodes large grid. I have a converged solution for a freestream velocity of 50m/s and I now want to simulate the flow at different freestream velocities. Unfortunately the residuals for the velocities, energie and continuity are beginning to oscillate after 100 Iterations in between 1e-1 and 2e-1 with an amplitude of around 1e-1 and no convergence is reached.

My Simulation parameters are: Solver: Coupled explicit parallel on 8 cpus Gas: Ideal Gas Law for Compressible Flows Turbulence: Realizable k-eps CFL: 0.2

Maybe a multigrid can solve the problem??? Thanks for any suggestions.


Razvan July 28, 2006 01:47

Re: Oscillating Residuals
Better try segregated solver. The velocity is low enough and it will converge much quicker. That, of course, if you cannot use coupled implicit solver due to memory limitations.


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