摘要

This paper presents experimental study on the influence of initial wall temperature distribution on the transient measurement results of cylindrical hole film cooling. Film cooling performance of cylindrical hole under two momentum ratios: 1 and 4, was measured. And three kinds of initial temperature distributions were used to calculate the film cooling effectiveness and the heat transfer coefficient: one is the real measured nonuniform initial wall temperature distribution, one is the temperature measured near the test surface, and one is the temperature measured far form the test surface. The results show that obtaining accurate initial temperature distribution is very important for transient heat transfer measurement of film cooling. Small overestimate or underestimate of the initial temperature by about 1°C ∼ 2°C can make the experiment results deviate from the true values more than 10%. The results of film cooling effectiveness and heat transfer coefficient could be lower than the true values if the used initial wall temperature is higher than the real, and higher than the true values if the used initial wall temperature is lower than the real. Moreover, the results show that the influence of inaccurate initial temperature on the experiment results is correlative with test duration time. In the region where test duration time is relatively long, the influence of inaccurate initial temperature is small relatively.