Recycling Compartment Re-entry Flight Characteristics Of The Process Study

Recovery capsule, which was boosted by engine, dropped down from 700 Km altitude, then reentered dense atmosphere at 80 Km altitude. During the reentry process, the large attack angle was maintained to produce more air drag in order to reduce the velocity of recovery capsule. When the altitude of recovery capsule was in 10～5km ,and the velocity, attitude met the design requirement, deceleration parachute was opened.In this paper, the aerodynamic shape and ballistic characteristics from its reentry movement to opening the parachute were studied. The deceleration process caused by air drag and the open condition of deceleration parachute of recovery capsule were analyzed.Compared with all kinds of reentry deceleration way of China and other countries in used, one approach was chosen. According to the approach of deceleration, the aerodynamic shape was designed. Based on the aerodynamic shape, the aerodynamic characteristics were obtained by engineering method and numerical simulation algorithm respectively. If the calculation results satisfied with the design requirement, the wind tunnel test was carried out to get the experimental data.The reentry trajectory simulation model of recovery capsule was established after aerodynamic design completion. The model was used to simulate the reentry process of recovery capsule. Reentry trajectory simulation models consisted of two parts: one is the standard, the other is interference ballistic trajectory mathematical model.Using the reentry trajectory mathematical model to simulate the movement of recovery capsule, the aerodynamic wind tunnel test data, structural parameters and initial parameters for reentry simulation were needed. First, the standard trajectory was calculated in order to analyze the reentry trajectory characteristics and judged the requirement to open the drag parachute, then the interference trajectory was calculated, by which the effect of single interference on ballistic characteristics were obtained, initial centroid and the value of pitch angle were determined. Finally, based on the Monte Carlo simulation, results of height range adaptive to open the parachute were presented under the action of interference.