Equation (7.1b) assumes that the boundary layer on the plate is turbulent from the leading edge onward.

Question:

Equation (7.1b) assumes that the boundary layer on the plate is turbulent from the leading edge onward. Devise a scheme for determining the boundary-layer thickness more accurately when the flow is laminar up to a point Rex,crit and turbulent thereafter. Apply this scheme to computation of the boundary-layer thickness at x = 1.5 m in 40 m/s flow of air at 20°C and 1 atm past a flat plate. Compare your result with Eq. (7.1b). Assume Rex,crit ≈ 1.2E6.

Equation (7.1b) assumes that the boundary