【摘要】 本文提出一种计算发散冷却火焰筒壁面温度的数值方法和相应的计算机程序;通过计算,可求出火焰筒的轴向壁温分布和热流分布。更多还原

【Abstract】 In 1983, Lefebvre, a well-known authority in this field, included in hisbook [1] a method for calculating wall temperature profile of flame tube withtranspiration cooling. No improvement on his method, to the author’s bestknowledge, has appeared in the open literature.Compared with Ref. [1],this paper is believed to provide the followingtwo improvements: （1） the following three factors affecting the accuracy of calculation areconsidered:① the longitudinol heat conduction in flame tube wall; ②the tempe-rature rise of cooling air in the annular cooling passage; ③ the effect of tempe-rature on physical properties. （2） Some experiments are not necessary. In Lefebvre’s calculation method,accurate values of cooling efficiency η and wall temperature ratio θ_T must be firstdetermined by experiment. The above two parameters η and θ_T are not employedin this paper, so experiments to determine them are not necessary. The following two conclusions, believed to be useful, are obtained in thispaper from the results of calculation: （1） The longitudinal heat conduction can not be neglected, because itsheat flux is of the same order of magnitude as that of C₂ convective heat flowbetween secondary cooling air and flame tube wall. （2） When the mass flow of the secondary cooling air is small, the tem-perature rise of secondary cooling air should be considered. Unfortunately no experimental data for transpiration cooling are available.Experimental data of the wall temperature profile of Spey-25 flame tubes whi-ch use film cooling are available. It is well known that transpiration-cooling isbetter than film cooling. When we use the same design parameters and workingconditions as those of Spey-25, the results of our calculations indicate that theflame tube with transpiration cooling has much lower wall temperature and moreuniform wall temperature distribution. This appears to indicate that the author’sproposed method gives reasonable results.更多还原