Correlation for ReTheta_c

The correlation for the critical Reynolds number Reθc is defined as follows:

1. EQUATION_DISPLAY
Reθc=CTU1+CTU2exp[CTU3TuLFPG(λθL)]
(1558)

where CTU1, CTU2, and CTU3 are Model Coefficients.

For the Gamma transition model, the quantities TuL and λθL are approximated locally as:

2. EQUATION_DISPLAY
TuL=min(1002k/3ωd,100)
(1559)

and

3. EQUATION_DISPLAY
λθL=min[max(7.57103d2ν(nv¯)n+0.0128,1),1]
(1560)

where:

  • k is the turbulent kinetic energy.
  • ω is the specific dissipation rate.
  • d is the distance to the nearest wall.
  • ν is the kinematic viscosity.
  • n is the wall-normal unit vector.
  • v¯ is the mean velocity vector.

For the SA Gamma transition model, λθL is given by Eqn. (1560) and TuL is a Model Coefficient.

The function FPG(λθL) is calculated as:

4. EQUATION_DISPLAY
FPG(λθL)={max[min(1+14.68λθL,1.5),0],λθL0max[min(17.34λθL,3),0],λθL<0
(1561)

Model Coefficients

Model VariantCTU1CTU2CTU3TUL
Gamma Transition100 1000 1 -
SA Gamma Transition10010000.60.01