Problems modeling vertical axid water turbine- divergence in AMG solvers

gambiss · March 7, 2011, 08:31

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Hi there,

I am having problems getting a model of a vertical axis water turbine to converge. For TSR2 it works perfectly with time steps size equal to half a degree, but for higher TSRs I kept getting divergence AMG solver (pressure). After playing around changing URFs and solvers, I finally managed to get it work by ioncreasing the timestep size to be equal to one degree for TSR3

But this is not the case for TSRs 4 and TSR5 and again I am having problems. Normally I get 'divergence' after about two rotations.

I have tried changing solvers, coupled, simple, simplec, piso and the URFs.

Thanks for your help in advance.

Emily

Oh. I am using Fluent 12.1 and a rotating mesh

gambiss · March 13, 2011, 14:05

Pleaasee can some one help me!?

March 7, 2011, 08:31	Problems modeling vertical axid water turbine- divergence in AMG solvers	#1
gambiss New Member Emily Join Date: Jan 2011 Posts: 13 Rep Power: 15	Tags Hi there, I am having problems getting a model of a vertical axis water turbine to converge. For TSR2 it works perfectly with time steps size equal to half a degree, but for higher TSRs I kept getting divergence AMG solver (pressure). After playing around changing URFs and solvers, I finally managed to get it work by ioncreasing the timestep size to be equal to one degree for TSR3 But this is not the case for TSRs 4 and TSR5 and again I am having problems. Normally I get 'divergence' after about two rotations. I have tried changing solvers, coupled, simple, simplec, piso and the URFs. Thanks for your help in advance. Emily Oh. I am using Fluent 12.1 and a rotating mesh

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March 13, 2011, 14:05		#2
gambiss New Member Emily Join Date: Jan 2011 Posts: 13 Rep Power: 15	Pleaasee can some one help me!?