高超声速滑翔飞行器驻点热环境不确定性量化评估

Uncertainty Quantification in Aerodynamics Heating for Hypersonic Glider Vehicle

高超声速滑翔飞行器面临复杂的气动热环境,预示数值存在一定的不确定度,其不确定度来源的辨识与量化分析对于确保可靠性和鲁棒热防护系统具有重要意义。首先给出了经过对比完善的高超声速滑翔飞行器端头、前缘和大面积气动加热计算方法。然后,将影响热流预示不确定性的因素分为认知不确定性和随机不确定性两类,分别给出了各个不确定性参数的概率分布类型和取值范围。最后采用蒙特卡洛法生成样本,以端头热环境为例,使用非侵入式多项式混沌方法和基于Sobol指标的方法开展不确定度量化和敏感性分析。分析结果表明,给定变量不确定条件下,端头热流不确定度不小于7.03%,且对来流速度和来流密度的变化更为敏感。

Hypersonic Glider Vehicle is faced with complex aerodynamic and thermal environment,which indicates that there must be some uncertainty in the numerical value.The identification and quantitative analysis of the sources of uncertainty are of great significance to the inspection and evaluation of aircraft.Fistly,the aerodynamic and thermal calculation methods of hypersonic vehicle’s nose,leading edge and large area are presented.Then,the factors that affect the uncertainty of heat flux prediction are divied into aleatory uncertainty and epistemic uncertainty,and the probability distribution types and value range of each uncertainty parament are given according to the experience.The monte carlo method is used to generate samples,and the nonintrusive polynomial chaos method and Sobol indices are used to analysis uncertainty quantification and sensitivity.The analysis shows that the uncertainty of stagnation point heat flux is not less than 7.03%under the condition of given inputs parameter uncertainty,and it is more sensitive to the velocity than density.