超燃冲压发动机燃烧室出口温度场分布CARS测量

针对超燃冲压发动机研究中对燃烧室出口温度场的测量需求以及暂冲式超燃冲压发动机燃烧台架试验中的应用难点，开发了适用于瞬态燃烧场温度测量的单脉冲相干反斯托克斯拉曼反射（CARS）系统及CARS光谱计算和温度反演软件CARSCF。采用USED相位匹配方式来降低湍流影响，结合多尺度小波分析方法来实现CARS光谱降噪处理，提高信噪比。在暂冲式脉冲燃烧风洞上开展了来流马赫数2.6条件下超燃冲压发动机燃烧室出口温度测量试验，获取了超声速来流（冷态）建立、H₂点火加热空气、建立超声速燃烧流场直至试验结束过程中的燃烧室出口温度，以及煤油/空气燃烧时燃烧室出口温度场分布。结果显示，超声速冷流时温度处于低温（约205K）状态，随着H₂点火加热来流空气，来流温度上升至853K；随着煤油/Air点火，温度急剧上升，稳定燃烧状态下燃烧流场温度为1970K±144K。燃烧室出口截面温度场分布测量结果显示，高温区位于燃烧室出口截面上侧区域，而燃烧室出口截面上中间区域的温度低于上下两侧。燃烧室出口温度分布CARS测量结果与火焰自发光成像结果一致，表明单脉冲CARS技术用于瞬态燃烧流场温度测量的可行性。

Outlet Temperature Measurements of Scramjet Combustor Using Coherent Anti-Stokes Raman Scattering

According to the requirement of combustor exit temperature distribution measurement and the difficulties of engine ground test in scramjet research, an USED-CARS system and a CARS spectra calculating and fitting program CARSCF are developed for instantaneous temperature measurement. The USED phase matching is used to reduce turbulence effects, the multi-scale wavelet analysis is used to reduce noise and to improve the signal-to-noise ratio. The CARS measurements of scramjet combustor exit temperature distribution with Mach 2.6 are performed at a pulse combustion facility. The temperatures of supersonic cold air flow, high temperature air and supersonic combustion are measured, the temperature distributions of combustor exit with different fuel-air equivalence ratio are obtained. The results show that the temperature of supersonic cold air flow is 205K at first, then rise to 853K with the air heating by H2 combustion. With the kerosene/Air igniting, the temperature increasing sharply to about 2000K with a fluctuation (i.e. standard deviation) of 144K at stable combustion state. The high temperature area of combustor exit is located on the upper side, the temperature of center area is lower than the upper and lower sides. The CARS measured temperature distribution of combustor exit are consistent with the results of flame chemiluminescence, indicate the practicability of single pulse CARS for instantaneous temperature measurement in practical scramjet combustion environment.