Abstract: Wind tunnel test is an important phase in the development of ram air parachutes. In this paper, the emphasis is put on the lift drag characteristic. By comparing the theoretical analysis with test result,the difference between flexible wing and rigid wing is introduced, and the optimum point of lift drag ratio is obtained. Meanwhile, the constitution of drag forces in the ram air parachute is also analysed, and the method to reduce the drag force is put forward.

Key words: ram a ir par achute, w ind tunnel t est, lift-dr ag char act erist ic