Wind-Tunnel Tests of a High Lift Generation and Stall/Spin Recovery System

Abstract

A novel aerodynamice ight control system, called the delta e ap, forthe generation of high lift and recovery from stall and spin was studied in wind-tunnel tests. A limited matrix of cone guration parameters, angles of attack, and Reynolds numbers were investigated. The delta e ap system consists of one or more slender delta-shaped e aps with a chord length typically less than one-third of the aircraft wing chord that are deployed close to the leading edge above the wing. The results of the study indicate that the delta e ap, deployed in a proper cone guration prior to stall, makes an aircraft wing virtually stall proof. Water-tunnel tests have also shown that deployment of the delta e ap at poststall angles of attack reverses e ow separation over the aircraft wing. Finally, wind-tunnel tests have proven that the delta e ap signie cantly increases the maximum lift coefe cient of the wing and reduces or reverses the nose-down pitching moment.