大气密度对运载火箭飞行的qα max 精度影响及建模分析

基于运载火箭是在真实大气密度中飞行，本文以2017年8月1日-2019年7月31日高垂直分辨率探空资料为例，分析参考大气密度与真实大气密度、以及对应的 qα max 之间差异特征，最后建立订正模型，研究结果表明：1)密度偏差、相对偏差随高度变化特征与季节有关，有较明显的年内变化特征；2)qα max 偏差随时间呈现“M”字型变化特征，其值范围为-217.1721～219.0648 Pa·rad，平均值为-9.4684 Pa·rad，在(-20，0］区间范围内占有率最大(20.4110%)；3)qα max 偏差具有明显的年内变化、季节变化特征，在1-3月和11-12月为正偏差、4-10月为负偏差，春、夏、秋季均为负偏差，冬季为正偏差；4)利用多元线性回归建立订正模型能较好地提高参考大气密度得到的qα max 精度，其中，偏差由-36.1569 Pa·rad减少到-7.7012 Pa·rad、绝对差由49.3254 Pa·rad减小到 20.3244 Pa·rad，因此，在分析大气环境对运载火箭飞行影响时，应采用真实大气密度代替参考大气密度进行计算。

Influence of Atmospheric Density onqαmaxAccuracy of LaunchVehicle Flight and Modeling Analysis

Based on the fact that a launch vehicle flies in the true atmospheric density, the sounding data in a certain region from August 1, 2017 to July 31, 2019 is used to analyze the difference between the reference atmospheric density and the true atmospheric density as well as their calculated qα max of a certain launch vehicle. Finally, a revised model is established, and the results show that: 1) The altitude related variations of the atmospheric density deviations and relative deviations of atmospheric density are related to the seasons, and there are obvious changes within a year; 2) The qα max deviation shows a “M” shape change characteristic with time, with the value range of -217.1721-219.0648 Pa·rad, the average value of -9.4684 Pa·rad, and the largest percentages (20.4110%) within the range of (-20,0］; 3) The qα max deviation also has obvious characteristics of annual and seasonal variation. From January to March and November to December there are positive deviations, and from April to October there are negative deviations, i.e. there are negative deviations in spring, summer and autumn, and positive deviations in winter; 4) Using the multiple linear regression method to establish a revised model can better improve the accuracy of qα max obtained from the reference atmospheric density, with the deviation reduced from -36.1569 Pa·rad to -7.7012 Pa·rad, and the absolute difference reduced from 49.3254 Pa·rad