典型尖楔结构燃气流热试验工况确定方法

在传统冷壁热流模拟方法的基础上,进一步提出以热壁温度及热流密度的时序变化曲线为控制目标的燃气流热试验工况确定方法,即利用壁温控制目标与实测值的偏差对热壁热流控制目标做一定修正,以尽可能消除和弥补前期试验误差,同时利用300K冷壁边界热流密度数据库插值迭代方法,快速确定一定气动热模拟所需燃气流温度,解决了沿飞行轨迹瞬态热试验技术难题之一。利用CFD数值模拟方法,建立了典型尖楔结构高/中温双路燃气流组合热试验300K冷壁边界热流密度数据库,并针对典型尖楔结构沿某飞行轨迹9个典型状态气动热模拟需求,确定相应双路燃气流热模拟参数。相关数值计算结果显示,驻点区域热流密度平均模拟偏差为4.5%,平板区热流密度平均模拟偏差为4.6%,两者最大模拟偏差均不大于8%,满足工程试验精度要求。同时,瞬态热分析结果显示第45s时,距驻点1mm处最大温度梯度达到21K/mm,距驻点10.1mm处最大温度梯度达到18K/mm,满足气动热大温度梯度效应需求。 

Determination method for thermal test condition of the tip wedge structure heated by high temperature gas flow

In view of to the traditional thermal test method based on the cold wall heat flux, a determination method based on the curves of the hot wall temperature and heat flux varying with time was proposed. Certain modification to the heat flux was made based on the deviation between the target and measured wall temperatures, in order to eliminate and remedy the test error during the earlier stage. And it determined the temperature of gas flow exactly and rapidly by interpolation in the database of the 300K cold wall heat flux, which solved one of the problems of transient thermal test along the trajectory. The heat flux database of tip wedge structure with variant gas flow rate and temperature was set up by CFD numerical analysis. The aerodynamic heating required for simulation of 9 typical conditions along a hypersonic flight trajectory was obtained and proved to be quite accurate for the requirements of engineering test by numerical simulation with the average error of heat flux of 4.5% in the stagnation point region, 4.6% in the rear plate region, and both maximum error of no more than 8%. The precision meets the requirements of engineering test. Moreover, transient thermal analysis results show that in forty-fifth seconds the biggest temperature gradient is 21K/mm and 18K/mm separately at 1mm and 10.1mm distance from the stagnation point, meeting the demand of high temperature gradient effect of aerodynamic heat.