高温高速气流冲击下气流挡板的换热性能研究

摘要

An oblique baffle was set behind the high temperature and high speed airflow nozzles in order that the air can flow along the baffle into the surrounding environment to decrease the affection around relevant personnels and equipments.For ensuring the use of the baffle,the heat transfer was analyzed and it was found the air layer on the baffle surface is the dominant factor. And the boundary layer stability is affected by the surface roughness and the baffle top edge angle. The influencial factors and their coupling characteristics under different operating conditions were studied by using the software FLUENT.The results show that the proper coating surface roughness can reduce the heat flux by 3%~7%,and the temperature of top surface of baffle by 10%.%在高温高速气流喷口后方设置倾斜气流挡板，使气流沿着挡板角度射入周围环境，达到减少对周围相关人员和设备的影响。同时为满足对挡板的使用要求，降低挡板表面的温度，对其换热过程进行分析，发现挡板表面空气层在换热中为主要影响因素。涂层表面粗糙度和挡板顶部边缘的锐角都会对边界层产生扰动，进而影响换热。采用 FLUENT 软件对挡板阻挡高温高速气流在不同工况条件下的影响因素及其耦合特性进行数值模拟仿真研究，结果显示，适当的涂层表面粗糙度，使传入挡板的热量减少3％～7％；挡板边缘倒圆角后，顶部温度下降10％。