高超声速高焓条件下的内嵌式温敏漆测量方法

MEASUREMENT METHOD OF EMBEDDED TEMPERATURE SENSITIVE PAINT UNDER HYPERSONIC HIGH ENTHALPY CONDITIONS

热流密度点测量结果并不能完全反映详细的热流分布特征,尤其是针对热流梯度较大、热流分布复杂的区域,需要热流密度场测量技术以获取全场精细的热流分布特征.应用温敏漆测量热流密度场的方法得到了广泛应用,但实验条件来流总温较低,与真实飞行环境存在明显差异,真实飞行条件下的辐射效应严重限制了温敏漆技术的应用.针对高超声速高焓条件下缺乏热流密度场测量方法的难题,提出了内嵌式温敏漆测量方法,基本思想是利用温敏漆测量内壁面温度的变化历程结合热传导反问题的求解确定热流密度.本文详细介绍了内嵌式温敏漆测量方法的测量原理、测量系统构成、数据处理方法、设计原则及该测量方法的优势.针对高超声速风洞实验中常见的阶跃、线性和局部突变等热流密度分布进行了数值验证,验证了内嵌式温敏漆测量方法的可行性,并分析了风洞实验温度测量精度及噪声对测量结果的影响.内嵌式温敏漆测量方法可用于测量高超声速真实飞行环境下细致的气动热特征,扩展了温敏漆测量方法的应用范围,解决了高超声速高焓条件下缺乏热流密度场测量方法的难题.

The heat flux measurement results of point sensors cannot fully reveal the detailed heat flux distribution characteristics, especially for the areas with large heat flux gradient and complex heat flux distribution. Measurement methods of heat flux field are needed to meet the demand. The method of temperature sensitive paint has been widely used to measure heat flux field. However, the stagnation temperature of the test condition is much lower than the real flight condition. The radiation effect under hypersonic high enthalpy conditions seriously limits the application of temperature sensitive paint. To solve this problem, the embedded temperature sensitive paint method is proposed. The heat flux field is determined by the solution of the inverse heat conduction problem with inner wall temperature history measured by temperature sensitive paint. In this paper, the measurement principle, system composition, data processing method, design principle and advantages of the embedded temperature sensitive paint method are introduced in detail.The feasibility of this method is verified by numerical simulation with typical heat flux distribution. Also, the influence of temperature measurement accuracy and noise on the measurement results are analyzed. The embedded temperature sensitive paint method can be applied in the hypersonic real flight condition to reveal the detailed characteristics of the heat flux field. This method extends the application of temperature sensitive paint and solves the problem of heat flux field measurement under hypersonic high enthalpy conditions.