双参数传热实验的液晶瞬态测量不确定度分析

以气膜冷却为例,利用多元隐函数求导的方法推导了双参数传热实验中采用液晶进行瞬态测量时的双参数不确定度计算关系式,采用不确定度传递系数研究了双参数不确定度与温度测量不确定度的关系,得到了不确定度传递系数随主流及二次流无量纲温度的变化曲线,分析了主流及二次流无量纲温度参数对双参数测量不确定度的影响.结果表明,提高主流温度或者增大两次测量中二次流的温差可以减小实验双参数测量不确定度.

Analysis of uncertainties in two-parameter transient heat transfer measurements with liquid crystal

This paper introduced a method of measuring heat transfer coefficient and dimensionless heat transfer temperature in transient film cooling measurements with liquid crystal,and through the uncertainties of heat transfer coefficient and dimensionless heat transfer temperature,analyzed the impact of dimensionless main flow temperature and dimensionless secondary flow temperature on two-parameters' uncertainties amplification parameters.The results indicate that,increasing the main flow temperature or increasing the difference between two measurements' secondary flow temperatures will decrease the uncertainties of heat transfer coefficient and dimensionless heat transfer temperature.