随机误差对容腔瞬态换热试验影响分析及抑制

针对容腔瞬态换热试验中测试数据的随机误差被数据处理的差分过程放大的问题，定量分析了随机测试误差对换热特性的影响，并提出抑制方法。结果表明:容腔内壁面对流换热特性误差对瞬态温度随机误差最为敏感，导致换热特性试验结果不确定度高。将改进经验模态分解（EMD）算法应用于数据差分处理过程中可以有效抑制测试随机误差对换热特性的影响。在容腔充气过程中，采用误差抑制方法后，容腔壁面换热特性的最大误差从129.07%降到63.62%，时均误差从25.24%降到8.12%。 

Influence analysis and suppression of random error on cavity transient heat transfer test

To solve the problem that the random error of the measurement data in the cavity transient heat transfer test is amplified by the differential process of data processing, the influence of random measurement error on the heat transfer characteristics is quantitatively analyzed, and the suppression method is proposed. The results show that the error of the convective heat transfer characteristic of the inner wall of the cavity is most sensitive to the random error of the transient temperature, resulting in high uncertainty of the test results of the heat transfer characteristics. The improved empirical mode decomposition (EMD) algorithm can be used in data differential process to effectively suppress the influence of random errors on the heat transfer characteristics. In the cavity inflation process, the maximum error of the heat transfer characteristics of the cavity wall surface decreases from 129.07% to 63.62% and the time average error decreases from 25.24% to 8.12% with the usage of error suppression method.