ibl.skin_friction.ludwieg_tillman

ibl.skin_friction.ludwieg_tillman(re_delta_m, shape_d)

Calculate skin friction coefficient using Ludwieg-Tillman (1950) relation.

This function calculate the skin friction given the momentum thickness Reynolds number and displacement shape factor and is based on experimental data on turbulent boundary layers from Ludwieg and Tillman.

If both parameters are numpy arrays, they have to be the same shape.

Parameters:

• re_delta_m (InputParam) – Reynolds number based on the momentum thickness

• shape_d (InputParam) – Displacement shape factor

Returns:

Corresponding skin friction coefficient

Return type:

InputParam