表面热流辨识技术在边界层转捩位置测量中的应用初步研究

A preliminary study for application of surface heat flux estimation technology in transition measurement

目前工程飞行试验中主要采用近壁热电偶测温法来确定飞行器表面流动的边界层转捩位置,由于测点离表面较近,对温度传感器量程和结构强度有较高要求。为此,提出了基于表面热流辨识技术确定转捩位置的基本思想和处理方法,测点可以距离表面相对较远。但是,当测点越远离受热面,辨识问题的不适定性会越强,因此需要采用仿真辨识方法来对传感器安装位置进行合理选取。在给出二维传热模型表面热流辨识算法的基础上,对两个算例进行了仿真辨识分析。结果表明:基于表面热流辨识技术确定转捩位置是可行的,能给出较为准确的转捩区域判断。

Near-surface thermocouples are the most prevailing devices to detect the boundary layer transition of flight vehicle in flight test.But some strict requirements for the measurement range of the thermocouple and the structural intensity are needed due to the small distance between the heating surface and the measurement position.So,a transition determination method based on surface heat flux estimation is developed.The advantage of this method lies in that the thermocouple can be placed relatively far from the heating surface.However,farther the thermocouple is placed,stronger is the ill-posedness of the estimation problem.So,when surface heat flux estimation method is applied for transition determination from interior temperature measurements,the measurement position is still needed to be carefully selected by simulation-based estimation strategy.The surface heat flux estimation method for two-dimensional heat conduction model is then presented in this paper and two cases are investigated with simulation-based estimation strategy.The results show that the transition determination method based on surface heat flux estimation is feasible and effective.