气膜冷却火焰筒壁温的数值计算方法

关于火焰筒壁温,文献1～4]均做过计算。一般采用了下列假定:①一维稳定紊流,②外套为绝热壁面,③忽略火焰筒内外壁面温差,④热辐射为一维模型,⑤忽略火焰筒壁面内的纵向导热,⑥忽略气膜段搭接处的接触导热,⑦忽略气膜段端面的对流换热,⑧忽略冷却空气在环形通道中的温升,⑨忽略物性随温度变化的影响。由于火焰筒为薄壁结构,③和④两假

NUMERICAL METHOD FOR CALCULATING WALL TEMPERATURE OF FLAME TUBE WITH FILM COOLING

This paper deals with a numerical method for calculating the wall temperature profile of turbo-jet flame tube with film cooling. The following factors affecting the accuracy of the calculation are considered: the longitudinal heat conduction in flame tube wall; the heat conduction at the interface of the film-cooled section with the corrugated strap; the convective heat transfer on two end surfaces of the film-cooled section; the temperature rise of cooling air in the annular cooling passage; the effects of temperature on physical propertres. A sample computation using this numerical technique is performed for calculating the temperature profile of the corrugated film-c.ooled sections of spey-25 flametubes. Owing to improvement of the calculation method, the obtained temperature profile agrees quite well with the experimental one.