高温燃气喷流/主流相互干扰实验研究

报道关于高温燃气自由喷流(热喷流)、燃气喷流/主流干扰流对气动热环境影响的实验研究结果. 其意义在于: 抽象出高超声速飞行器实际飞行时燃气喷流及其干扰流的物理模型, 为高超声速飞行器防热需求提供实验依据. 实验主流由脉冲风洞提供,燃气喷流用氢氧燃烧驱动路德维希管的方式产生. 利用脉冲风洞驱动段压力信号自动控制热气源的产生以保证风洞主流与燃气喷流同步, 利用氢气、氮气和氧气的不同比例实现燃气喷流的热力学相似. 实验技术上完成了高温燃气喷流系统的参数采集与系统状态标定; 实验内容上开展了压缩拐角平板模型的气动热实验研究, 通过实验比较了只有主流流场、只有热喷流流场和既有主流流场又有热喷流流场(即干扰流场)3种工况的热流分布. 实验研究发现,热喷流/主流相互干扰会对压缩拐角平板上某一范围内的气动热环境造成显著影响, 热流峰值较无喷流流场高出一个量级. 

THE INVESTIGATION OF EXPERIMENTAL TECHNIQUE FOR HIGH TEMPERATURE GAS JET FLOW TEST IN IMPULSE WIND TUNNEL

This is the first report on the experimental results about the aerothermal environment of high temperature jet flow(HTJF) and its interaction flow.The significance of this experiment is to abstract the physical mode from the real flight of hypersonic aircraft in order to provide experimental evidence for the thermal protection requirements.This experiment used the compression corner as the research object to research the aerothermal environment influenced by the HTJF and the interaction flow by the HTJF in combine with the main flow filed.In this paper,the main flow came from the impulse wind tunnel;the HTJF came from the high enthalpy gas supply platform,which used the ox-hydrogen burner to drive the Ludwieg tube.This paper used the pressure change of the driven section in the impulse wind tunnel to control the producing of the HTJF in order to assure the synchronous operation of the two parts of flow.This paper will present the research about: (1) To standardize the thermodynamic state of the HTJF;(2) The experimental research of the compress corner which include three experimental status:(i) the aerothermal environment in the main flow without the HTJF; (ii) the aerothermal environment in the high temperature jet flow without the main flow;(iii) the aerothermal environment in both the high temperature jet flow and the main flow.It is found from the experiment that the aerothermal environment of the part of the compress corner has great influenced by the high temperature gas flow.The high temperature gas jet flow can cause the heat flux peak an order of magnitude than the heat flux peak without it.