BC Profile with Turbulent Intensity

blackbody · May 13, 2010, 04:36

hi everybody!

can i use turbulent intensity (%) as a profile boundary condition?
when i look at the "standard variable names" in CFX helper i only
see that i can specify k (turbulence kinetic energy) as a profile bc parameter.
if i use k in the profile BC, than CFX ask me for epsilon (turbulent dissipation rate). i dont have epsilon though....
any suggestion?

thank you very much!

ghorrocks · May 13, 2010, 08:10

Turbulence intensity % just defines the turbulence intensity (k) as a function of flow velocity. It does not define the second variable required to specify the turbulence inlet condition. You will need to specify an epsilon, turbulence length scale, turbulence viscosity scale or some other independent turbulence parameter to define the second turbulence variable.

May 13, 2010, 04:36	BC Profile with Turbulent Intensity	#1
blackbody Member Join Date: Feb 2010 Posts: 33 Rep Power: 16	hi everybody! can i use turbulent intensity (%) as a profile boundary condition? when i look at the "standard variable names" in CFX helper i only see that i can specify k (turbulence kinetic energy) as a profile bc parameter. if i use k in the profile BC, than CFX ask me for epsilon (turbulent dissipation rate). i dont have epsilon though.... any suggestion? thank you very much!

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May 13, 2010, 08:10		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,854 Rep Power: 144	Turbulence intensity % just defines the turbulence intensity (k) as a function of flow velocity. It does not define the second variable required to specify the turbulence inlet condition. You will need to specify an epsilon, turbulence length scale, turbulence viscosity scale or some other independent turbulence parameter to define the second turbulence variable.