主喷管叶片中热壁面对分流管道流场特性的影响

Effects of hot wall on flow field characteristics of distribution flow pipeline in primary nozzle blade

连续波化学激光器运转时,位于主喷管叶片内的副气流的分流管道壁面将被主喷管叶片加热而形成热壁面。通过3维的数值模拟,分析了单端、双端不同供气方式下,热壁面对分流管道流场特性的影响。热壁面将使总管气流总温沿着气流的流动方向逐渐升高,由此引起的支管入口总温的升高会降低支管的流量。无论是单端供气,还是双端供气,热壁面引起的管道流量波动幅度都要远大于绝热壁面的情况,最大波动幅度达2.16%。对进入总管的气流预热,适当增加供气总温,或将冷却管道与供气管道分开设计,气流总温变化引起的流量波动将会得到一定地抑制。

The wall of secondary gas flow distribution pipeline in primary nozzle blade will be heated during CW chemical laser operation.Effects on flow field characteristics of distribution flow pipeline with hot wall boundary under conditions of single end or double ends gas supply were analyzed based on three-dimension computational fluid dynamics methods.The hot wall boundary makes the total temperature of general pipeline higher and higher along the direction of main gas flow movement,and the total temperature of branch pipeline inlet goes up simultaneously,which results in corresponding decrease in mass flow rates of branch pipeline outlets.The fluctuating amplitude of mass flow rates of branch pipeline outlets with hot wall boundary is bigger than that with adiabatic wall boundary,and the maximal fluctuating amplitude goes up to 2.16%.In addition,two methods that will effectively alleviate the fluctuation of mass flow rates owing to total temperature＇s increasing of branch pipeline were presented.One is increasing total temperature of gas supply reasonably;the other is separating gas-cooled pipelines from gas supply pipelines.