Analysis of Strake Vortex Breakdown Characteristics in Relation to Design Features

Abstract

This paper describes a water-tunnel study of the vortex breakdown characteristics of a large number of analytically designed vortex strakes tested in combination with a moderate-aspect-ratio trapezoidal wing. A wide range of strake sizes and slenderness ratios are covered, and examples of the effects of the primary design parameters of size, span, and slenderness on the vortex breakdown characteristics are presented and analyzed in relation to the three-dimensional leading-edge suction distributions. Several examples of detailed planform shaping on strakes of the same general size and slenderness are shown. From these it is demonstrated that vortex stability can be improved by satisfying the design criterion. The criterion states that those shapes having leadingedge suction distributions which increase more rapidly near, and have a higher value at, the spanwise tip of the strake promote vortex stability. A AD b C c cr ( cr ) w cs ED Kv / p