抛盖动力和“零-零”抛盖过程研究

Study of Jettison Dynamic Force and "Zero-Zero" Jettison

在分析"零-零"抛盖过程的基础上,建立了模拟作动系统进气及作动筒和舱盖运动过程的数学模型,实现了"零-零"抛盖过程作动筒上下腔压力变化的准确模拟,解决了以往研究中抛盖动力需要大量试验数据的问题。经过无量纲处理"零-零"抛盖试验中自由抛放阶段舱盖的运动轨迹,澄清了"零-零"抛盖过程自由抛放阶段可以忽略气动力的问题,并通过考虑和不考虑定轴转动阶段气动力两种情况下,"零-零"抛盖过程舱盖轨迹预测值与试验结果的比较,说明了考虑定轴转动阶段气动力会与实际情况更为接近。

Based on a detailed analysis of ＂zero-zero＂ jettison,the study presents several numerical models for simulating the charging process of an actuating system and motions of the actuating cylinder and canopy. Through solving the above models,the pressure changes in the upper and lower chambers of the actuating cylinder are accurately predicted,which makes up for the shortage of data from dynamic force experiments in previous studies. To study whether or not it is necessary to consider aerodynamic forces in the prediction of ＂zero-zero＂ jettison,non-dimensional transformations of canopy trajectories in ＂zero-zero＂ jettison tests are performed. It is found that the impact of aerodynamic forces can be neglected in the prediction of the free-jettison step of the ＂zero-zero＂ jettison process. Furthermore,canopy trajectories at the axis-rotated step of the ＂zero-zero＂ jettison are predicted with and without considering aerodynamic forces. Comparisons of the test results indicate that prediction results which take aerodynamic forces into consideration are closer to experimental results.