Realizable k-epsilon model for cavity flows

vasuaero1988 · September 24, 2010, 08:20

hi!!!! m' working on study over cavity flows. m' trying to simulate the cavity unsteady flows using Realizable k-epsilon model with enhanced wall treatment as it has superior performance involving flow rotations and recirculation. i've tried with all other turbulence models, the results were not satisfactory. during iterations using Realizable k-epsilon model m' gettng some message as "Turbulence viscosity limited to 1e-5". i have tried with differnt types of intensity and viscosity ratios in the inlet boundary condition panel. the problem is not solved. There must be some other conditions for Realizable K-epsilon model which m' missing. i need some assistance in this regard. All the conditions for using Realizable k-epsilon is also expected. The y+ value near the wall for my model is 6.4.

Mohsin · September 27, 2010, 03:06

You wont get this message if you change the limits of Turbulent visocisty ratio.

Go to Fluent--->Solve...>Controls....>Limits...>maximum Turbulent Intensity ratio....(Increase this to say 10^9) You can increase to the point where u will not get this error.

Hope this helps.
Mohsin

September 24, 2010, 08:20	Realizable k-epsilon model for cavity flows	#1
vasuaero1988 New Member Srinivasan Join Date: Aug 2010 Posts: 5 Rep Power: 15	hi!!!! m' working on study over cavity flows. m' trying to simulate the cavity unsteady flows using Realizable k-epsilon model with enhanced wall treatment as it has superior performance involving flow rotations and recirculation. i've tried with all other turbulence models, the results were not satisfactory. during iterations using Realizable k-epsilon model m' gettng some message as "Turbulence viscosity limited to 1e-5". i have tried with differnt types of intensity and viscosity ratios in the inlet boundary condition panel. the problem is not solved. There must be some other conditions for Realizable K-epsilon model which m' missing. i need some assistance in this regard. All the conditions for using Realizable k-epsilon is also expected. The y+ value near the wall for my model is 6.4.

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September 27, 2010, 03:06		#2
Mohsin Senior Member Mohsin Mukhtar Join Date: Mar 2010 Location: South Korea Posts: 249 Rep Power: 17	You wont get this message if you change the limits of Turbulent visocisty ratio. Go to Fluent--->Solve...>Controls....>Limits...>maximum Turbulent Intensity ratio....(Increase this to say 10^9) You can increase to the point where u will not get this error. Hope this helps. Mohsin