how to calculate Cf inside a wall function
Dear foamers,
Could you tell me how to calculate Cf (friction coefficient) inside a wall function like alphatWallFunctionFvPatchScalarField.C ? I already have yPlus, rho and uStar=Cmu^(0.25)*k^(0.5). Code:
forAll(mutw, faceI) In order to be more accurate, can I calculate uTau with lines below? Code:
const fvPatchVectorField& U = Code:
scalar utau = 1) I know that I can recalculate the uPlus with yPlus to get sqrt(Cf/2), since uPlus=1/sqrt(Cf/2) 2) If I use the other definition of uPlus, the problem will be to know Ue in order to find Cf=tau/(0.5*Ue*Ue*rho). uPlus= Up*Cmu^(0.25)*k^(0.5)/(tau/rho) Even I adopt such calculation, how to get value of Up? Is it simply U[faceI]? I would like to know whether or not there is an easier way. Are the methods above acceptable? Are they correct in programming? Regards, aerothermal 
No clues on that?

All times are GMT 4. The time now is 00:37. 