Skewed turbulent boundary layers

Abstract

The problem of predicting the growth of incompressible, skewed, turbulent boundary layers on smooth surfaces is considered. It is supposed that sufficient initial information and a complete knowledge of the external pressure distribution is given. A computation scheme is devised which makes use of the two momentum integral relations and an auxiliary equation. The formulation of the latter is based on the empirical observation that if a velocity profile is plotted in a holograph plane the outer portion is nearly always linear. A theoretical means of describing velocity distributions is formulated. These theoretical profiles contain two "universal"- functions and five parameters that are functions of the surface coordinates only. The "universal" functions are derived analytically and. compared with experiment. Finally, a comparison of theoretical and experimental velocity profiles suggests that the proposed computation scheme is only applicable to situations where gradients of flow quantities in the cross-flow direction are not too large. Therefore, the scheme is probably better suited to the external flow over wings, etc., than to flows in turbomachinery.