[Bran]

Hello,

I am working on improving my meshing abilities and I came across the inflation feature that allows you to resolve the viscous sublayers close to the wall.

I have confusion when it comes to determining the most suitable cell height.

I utilize the following equations:
Re = (rho*U*L) / mu
y = ((y+)*mu) / U_tau*rho
U_tau = sqrt(tau_w / rho)
tau_w = 0.5*C_f*rho*U^2

where:
U_tau is dimensionless velocity at the wall
tau_w is the wall shear stress
C_f is a friction coefficient

Would I use these equations to determine y which would allow me to choose a suitable first wall height?

How can I find C_f?

Thank you.

[FMDenaro]

Yes, using the characteristic lenght L you can also write directly



y/L =y+/Re