[user2296]

Hello,

does someone know the boundary conditions for the turbulence model of Spalart-Allmaras (SA) for a lid-driven cavity boundary value problem? I did not find any thesis or paper where it is explained.
In general, the variable of the SA equation is set to zero at walls and three up to five times the kinematic viscosity at the inlet. Therefore, I wonder if I must set the variable of the SA to zero or not.

Thank you

[LuckyTran]

You don't find publications because it is an art, not a science. The 5 times viscosity corresponds to the very very very turbulent inflow. If you want a laminar inflow then you want to set it to 0. Except some implementations are unstable with a 0 nutilda inlet and you must specify a slightly positive number that isn't zero that stays laminar and doesn't blow up. Now because it is an art, make sure you also don't tell anyone else what number you used XD.

[user2296]

Originally Posted by LuckyTran

You don't find publications because it is an art, not a science. The 5 times viscosity corresponds to the very very very turbulent inflow. If you want a laminar inflow then you want to set it to 0. Except some implementations are unstable with a 0 nutilda inlet and you must specify a slightly positive number that isn't zero that stays laminar and doesn't blow up. Now because it is an art, make sure you also don't tell anyone else what number you used XD.

Thanks for your answer, it was very helpful