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Old   July 27, 2006, 04:50
Default Oscillating Residuals
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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.

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Old   July 28, 2006, 01:47
Default Re: Oscillating Residuals
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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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