# boundary and initial condition for SST k-omga turbulence model

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 April 17, 2012, 23:47 boundary and initial condition for SST k-omga turbulence model #1 Senior Member   Mehdi Baba Mehdi Join Date: Jan 2011 Posts: 158 Rep Power: 15 Hi everyone. I am writing self-developing code and I want to apply SSt k-omega turbulence model for simulation of flow over a flat plate. but I can't find any good references that has and explains boundary and initial conditions for external flow. I find some that have different boundary, esp. for inlet and far-filed. for example, in some references propose that viscosity ratio (Mut/Mu) should be between 1 and 10 and also turbulence intensity and using these two, value of k and omega in inlet can be calculated as follow: Inlet: (kinlet=1.5*(turbulence intensity*free stream velocity)^2 , Mut=(1-10)*Mu omegainlet=ru*kinlet/mu*viscosity ratio) far field boundary: Omegainf>10*free stream velocity/L L: characteristic Length Mutinf<10e-2*Mutmax Kinf=Mutinf*omegainf/ru but I should mention in some paper constant numbers are different. in some paper or user's guide suggest that turbulence intensity set between 1-10%. My problem is these boundary layer is correct and how can specify viscosity ratio and turbulence intensity in specified Re? And if any good reference explain it, I really appreciate letting me know. Thanks in advance.

 April 18, 2012, 20:26 #2 Senior Member   Join Date: Nov 2009 Posts: 411 Rep Power: 19 Turbulence modelling for CFD by Wilcox: http://www.amazon.com/gp/product/192...SIN=1928729088

 April 19, 2012, 01:28 #3 Senior Member   Mehdi Baba Mehdi Join Date: Jan 2011 Posts: 158 Rep Power: 15 Thank you so much DoHander. I read the book that you introduce, but I can find any boundary condition for inlet and freestream in external flow. Are you sure these boundary conditions were introduced in the book? and if yes, could you please tell me which part of this (I know in part 7.2.2 was talked about turbulent/non-turbulent interfaces, But boundary conditions were not introduced). Thank you. Last edited by mb.pejvak; April 19, 2012 at 01:46.

 May 1, 2012, 20:06 #4 Senior Member   Mehdi Baba Mehdi Join Date: Jan 2011 Posts: 158 Rep Power: 15 I found a good paper "Effective Inflow Conditions for Turbulence Models in Aerodynamic Calculations" by Spalart and Rumsey that explained inflow boundary condition for SST k-omega and SA turbulence models and also they recommended inflow boundary condition for these two models.