Wall function

K. Yamamoto

Hi, experts.

I have the following two questions.

(1) In AcuSolve, the wall function can be selected in the model using SST k-omega turbulence model. In this case, will the calculation near the wall be performed using the wall function instead of k-omega, and will the result be the same as the standard k-epsilon?

(2) When a wall function is applied and there is no calculation point between the wall surface and the buffer layer, how is the flow in the first mesh layer near the wall surface calculated? Is the entire first mesh layer considered to be a turbulent layer, and is the logarithmic law of the wall function applied?

acupro

You can find a description of the wall function application here - in the TURBULENCE_WALL command.  It would also apply for SIMPLE_BOUNDARY_CONDITION with type = wall.

https://help.altair.com/hwcfdsolvers/acusolve/topics/acusolve/turbulence_wall_acusolve_com_ref.htm

From that page:

Unlike some wall function implementations there is no minimum requirement in AcuSolve. For small values of the two types (wall_function and low_reynolds_number) become equivalent.