Study on the improvement of stall characteristics of civil aircraft in wind tunnel test

Abstract In order to improve the stall characteristics of civil aircrafts and increase the maximum available lift coefficient, this paper studied two types of aerodynamic combination measures through wind tunnel test--the inner slat gap seal and outer slat modification, as well as the inner slat stall bar and outer slat modification. The test results showed that the combination measures of the inner slat gap seal and outer slat modification can make the horizontal roll stall divergence angle at least 1° greater than the longitudinal stall angle of attack, and the turning roll stall divergence angle is at least 2° later than the longitudinal stall angle of attack. The combination measures of the inner slat stall bar and outer slat modification can make the horizontal roll stall divergence angle about 2° greater than the longitudinal stall angle of attack, and the turning roll stall divergence angle is also about 2° later than the longitudinal stall angle of attack. The test results indicate that the two types of aerodynamic combination schemes can improve the stall characteristics and change the stall type into the longitudinal stall.