kappatJayatillekeWallFunctionFvPatchScalarField changes between OpenFOAM 171 and 201

mabinty · February 25, 2014, 13:42

hey Camoesas!

in the routine you posted, yPlusTherm, yPlus where the linear and the log law intersect, is calculated with the help of Newton's method. the function "f" is the difference of the linear function (laminar sub-layer) and the log-function which becomes zero for ypt = yPlusTherm.

VSMALL is a very small number mostly used in the denominator of a quotient to avoid a division by zero.

hope that helps!

cheers,
aram

camoesas · February 28, 2014, 02:50

HI Aram!

Thanks for your fast Reply!
I got that, but why do i have the turbulent Prandtl-number (Prat) in the denominator? Equation for f? The jayatilleke Wall function in the enominator!
What kind of function for the thermal laminar sublayer is used? It seems that it simply is: T+ = y+ , shouldnt it be something like T+ = y+ * Pr_l ???

Thanks!

Camoesas

February 28, 2014, 02:50		#22
camoesas Senior Member Join Date: Mar 2009 Posts: 138 Rep Power: 17	HI Aram! Thanks for your fast Reply! I got that, but why do i have the turbulent Prandtl-number (Prat) in the denominator? Equation for f? The jayatilleke Wall function in the enominator! What kind of function for the thermal laminar sublayer is used? It seems that it simply is: T+ = y+ , shouldnt it be something like T+ = y+ * Pr_l ??? Thanks! Camoesas __________________ OF - 2.0.0

February 25, 2014, 13:42		#21
mabinty Senior Member Aram Amouzandeh Join Date: Mar 2009 Location: Vienna, Vienna, Austria Posts: 190 Rep Power: 17	hey Camoesas! in the routine you posted, yPlusTherm, yPlus where the linear and the log law intersect, is calculated with the help of Newton's method. the function "f" is the difference of the linear function (laminar sub-layer) and the log-function which becomes zero for ypt = yPlusTherm. VSMALL is a very small number mostly used in the denominator of a quotient to avoid a division by zero. hope that helps! cheers, aram