Laminarization of boundary layer on a wing profile by distributed suction

Abstract

A theoretical study is undertaken of boundary-layer laminarization on a wing profile by means of distributed suction on the basis of the Prandtl equations and general considerations of hydrodynamic stability theory. The influence of various aerodynamic and geometric characteristics of the profile on the value of the minimum suction air flow coefficient is examined. Specific examples are presented of the calculation of

$$(M,R_\infty ,\alpha ,\bar c),C_{Q\min } .$$

A rather extensive bibliography of works on this problem may be found in [1]. In these studies the methods for solving the boundary-layer equations are usually based on approximate integral relations, which in many cases are not sufficiently accurate for the solution of those problems posed by artificial flow laminarization.

In the following the boundary-layer equations are solved numerically on a computer, using a difference method [2]. The problem of the optimum distribution of the suction intensity over the wing profile is solved on the basis of general considerations of stability theory [3]. We consider the effect of various profile aerodynamic and geometric characteristics (M, R_∞,α,¯c) on the magnitude of the minimum suction air flow which will laminarize the flow under given conditions.