应用红外热像技术实验研究层板结构冷却特性

在高温热风洞中,应用红外热像系统对三个具有真实燃气轮机尺度的层板结构进行了冷却特性实验研究.为了描述冲击、对流及导热的综合作用,采用数字图像信号运算技术,直接获得描述冷却前后层板高温表面二维温差分布.通过比较三种层板结构综合冷却效率,详细讨论了绕流柱数目及直径、气膜孔角度、主流雷诺数和努塞尔数对层板冷却效率的影响. 

Experimental investigation on cooling performance of laminated configuration using infrared thermal imaging technique

To investigate the geometrical performance of laminated film cooling configurations, surface temperature distributions of three different specimens with the true size of gas turbine components were measured by an infrared thermal imaging system. Experiments were carried out in the hot gas wind tunnel of UTSC. To describe the overall cooling effect contributed by coolant impingement, heat conduction and convection, an algorithm of digital imaging signal was used, and the two-dimensional temperature drops from initial wall to cooled wall were directly obtained. Through comparisons of the cooling performance of the three specimens, the effects of the number and diameter of columnar ribs, the angle of film holes, the Reynolds number and Nusselt number of free stream on the overall cooling effectiveness were discussed.