随机误差对容腔瞬态换热试验影响分析及抑制

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.