高速飞行器热防护结构非均匀热流载荷反演方法

Inversion method of non-uniform heat flux loadof thermal protection structure for high-speed aircraft

为准确掌握高速飞行器热防护结构服役时承担的非均匀气动热载荷,提出了一种基于共轭梯度理论的非均匀热流载荷的反演方法.以隔热瓦结构为例,开展了2类典型非均匀热流载荷下的数值仿真研究.通过引入一阶样条曲线插值表征非均匀热流的时变规律,降低了待反演参数数量.分析了反演方法的可行性以及温度测量偏差等因素对反演精度的影响.研究结果表明:非均匀热流时变规律的样条线表征方法可以将反演参数数量缩减到4个,极大地提升了反演效率;提出的反演方法可以精确反演结构非均匀热流载荷的时间和空间分布特性,对于含噪声的测量数据,该方法由于采用了插值重构的表征方法而体现出较好的抗噪性能.

To accurately grasp the non-uniform aerodynamic thermal load borne by the thermal protection structure of high-speed aircraft in service,an inversion method of non-uniform heat flow load was proposed based on the conjugate gradient theory.Two kinds of typical non-uniform heat flow loads were studied using the heat insulation tile structure as an example.By introducing first-order spline curve interpolation to characterize the time-varying law of non-uniform heat flow,the number of parameters to be inverted was reduced.The feasibility of the inversion method was analyzed,and the influence of temperature measurement deviations on inversion accuracy was studied.The results show that the number of inversion parameters can be reduced to 4 using the time-varying spline characterization method,which greatly improves the inversion efficiency.The proposed inversion method can accurately invert the time and space distribution characteristics of the non-uniform heat flow load.For the measurement data containing noise,it shows good anti-noise performance due to the use of interpolation reconstruction characterization method.