尖楔结构低速高/中温双路气流组合热试验方法

Combined heating method of low speed and high/middle temperature gas flow for thermal test of tip wedge structure

在典型高超声速飞行工况下,数值模拟分析了高温合金尖楔前缘结构沿气流方向大温度分布梯度将带来严重的热强度问题,产生大温度分布梯度的根本原因是尖楔结构头部区域平均热流密度与后段平板区域平均热流密度之差,而受头部区域热流密度具体分布的影响不大;进而提出了一种低速高/中温双路气流组合热试验方案,并通过数值模拟方法证明了该方案具有两股气流参数可以独立调节分别满足尖楔结构头部驻点区域及后段平板区域大、小两种热流密度的优点,进而解决单喷口低速高温燃气流热模拟试验难题,满足尖楔结构高超声速飞行工况下大温度梯度模拟要求.同时,该方案通过高/中温气源的合理组合搭配可以大大降低尖楔结构热试验所需高温气源发生功率,推广应用于电弧风洞可拓展其热试验范围.

The big temperature gradient in hypersonic tip wedge structure was calculated and simulated,and key thermal simulation parameters were presented.Since the single spout heating method can not simulate the heat flux density satisfactorily on the rear plate,a dual-mode heating method was developed to solve this problem,covering a high temperature flow with small spout in the center enveloped by a lower temperature flow.A typical hypersonic condition was simulated using CFD method.It shows that this new heating method can accurately simulate the hypersonic heat flux distribution of the tip wedge by effectively meliorating the heat flux distribution on the rear plate and maintaining the high heat flux density on the stagnation zone.The simulation of transient temperature distribution and big temperature gradient in the interior of tip wedge structure also gets very good results to support this strategy.Meanwhile,the dual-mode heating method can not only greatly reduce the spout size and speed of high temperature flow,but also greatly improve the test ability of electric arc wind tunnel to satisfy larger size of tip wedge structure.