Study On Testing Techniques Of The Parachute Opening Process

As a widely used tool in aviation and aerospace field, the inflation process of theparachute is seen as the most complicated phase when the parachute opens in variousapplications. The parachute opening overload is an important indicator for evaluating itsperformance, as its value is directly related to the choice of the parachute form, the reliabilityof the connecting mechanism in parachute-object system, the performance of on-boardequipment, whether protection of the aerial bomb fuse is removed, etc.First of all, this paper deduces the dynamic equations of parachute inflation process byconsidering parachute shape changes based on relative theories of Aerodynamics and Physics.The Eulerian method is used to calculate the mathematical model, from which results areobtained and analyzed including the straightening speed, the opening height, impacts of theresistance characteristics on the opening overload.Secondly, an airborne delivery parachute opening overload recorder is designed in thispaper to record and analyze the complicated changes in the parachute opening process. Thispaper elaborates the characteristics of parachute opening overload signals, the design schemeof the acceleration testing system, the circuit design as well as the program flow design. Thetesting device is equipped with low power consumption, a smaller testing range with a higheroverload, the ability to collect three-axis acceleration signals, a long enough sampling timeand also a large storage capacity. Moreover, it is capable of saving data safely when power isoff and can be re-trigger four times.Finally, the reliability of airborne delivery parachute opening overload recorder isconfirmation by environmental testing. A dual track rocket sled experiment is performed usingthe designed airborne delivery acceleration and an aerial bomb. The experimental scheme is introduced in details and testing data are analyzed in this paper.