Application of scan pitot-pressure rake in hypersonic propulsion wind tunnel flow field measurement

在风洞实验中,为了保证实验结果的可靠性,首先需要了解流场的品质.笔者自行设计研制了用于高超声速推进风洞流场测量的带有水冷装置的可移动式扫描总压耙.对于出口截面为300mm×187mm的风洞喷管,通过计算机程序控制,可在3s时间内实现全截面间歇式或连续式扫描,最大移动速度可达250mm/s,而且定位准确.通过扫描结果,分析了流场压力均匀性、稳定性以及实验结果的可重复性,同时还给出了风洞喷管出口截面的总压与马赫数等值线图.从而为超燃冲压模型发动机实验提供参考数据

PDE/Scramjet组合循环发动机实验研究

本文对一种新概念的PDE/Scramjet 组合循环发动机在自由射流推进风洞中进行了实验研究。着重研究了点火、凹腔对发动机性能的影响。实验发现, 由爆轰管尾部带来的大扩张结构需要强制点火才能保证超燃发动机的稳定燃烧。此外发动机侧面凹腔的引入，对性能有利也有弊，需要进一步权衡。本文还开展了PDE/Scramjet 的联合实验，由于PDE 燃料流量只有超燃发动机的1%左右，导致PDE 对整体发动机性能贡献很小。最后，本文还采用总压恢复模型对组合循环发动机的推力阻力进行了分析

Performance of the fuel injector in supersonic combustor

Enhancing the fuel-air mixing is critical for scramjet combustor performance. The performance of four different aerodynamic ramp injectors was reported in this paper. The experiments were conducted in a direct-connected scramjet test facility. The concentration profiles were obtained by gas sampling and chromatogram analysis. The pictures of the flow field were obtained by using laser scatter. It would be used to analyze the flow field generated by the aerodynamic ramp, then optimize the layout of the injectors. The results would offer some useful information for engine design. Copyright © 2009 by the American Institute of Aeronautics and Astronautics, Inc

Measurement of temperature, velocity and water vapor concentration in a scramjet combustor based on nearinfrared diode laser absorption

A multi-channel Tunable Diode Laser Absorption Spectroscopy (TDLAS) system was designed and constructed for flow parameters diagnostics in a scramjet combustor. Two fiber coupled distributed feedback (DFB) lasers with narrow line width were used to probe two H2O absorption features (7185.597cm-1,7444.35cm-1+7444.37cm-1(c ombined)) by using direct absorption Time-Division-Multiplexing (TDM) strategy at a 4-kHz repetition rate. Laser light was split into five beams and transmitted across the test region. Two motorized precision translation stages were used to move the collimators during the test, so that the three beams located near the cavity and at the exit of the combustor can scan the cross sections respectively. Flow parameters could be obtained simultaneous which included average temperature, water vapor concentration and velocity at the entrance of the combustor, the distribution of temperature, water vapor concentration at a cross section near the cavity, the distribution of temperature, water vapor concentration and velocity at the exit cross section of the combustor. The parameters of the flow entering and exiting the combustor could be used to evaluate the performance of the direct-connected scramjet facility and the combustion efficiency of the combustor. The parameters at the cross section in the combustor could also be used to analysis combustion characteristics in the combustor

智能压力扫描系统

高精度的压力测量系统，通过电子扫描方式，主要技术指标: 128通道，绝压45PSI量程，精度0.05%，扫描频率100H

Investigation for Effects of Jet Scale on Flame Stabilization in Scramjet Combustor

Jet scale affects the mixing and combustion of fuel and inflow. With the increase in the scale of scramjet combustors, the study of large-scale jets is particularly significant. The effects of jet scale on flame stability in scramjet combustors were studied by direct-connect combustion experiments. In this paper, the flame distribution characteristics of different jet scales were compared by using similar jet/inflow momentum ratios. The inflow Mach numbers were 2.4 and 3.0, and the total temperature was 1265 K and 1600 K, respectively. The results show that, when the equivalence ratio increases, the combustion intensity increases. Under the condition of same momentum ratio, the increase of jet scale is conducive to fuel injection into the core mainstream, increasing heat release, and the flame stabilization mode will change from cavity stabilization mode to jet-wake stabilization mode. Increasing the distance between jet orifices is not beneficial to combustion, and may even lead to blowoff

Experimental investigation on the cavity-based scramjet model

The present work focused on improving the engine performance with different fuel equivalence ratios and fuel injections. A scramjet model with strut/cavity integrated configurations was tested under Mach 5.8 flows. The results showed that the strut may sreve as an effective tool in a kerosene-fueled scramjet. The integration of strut/cavities also had great effect on stablizing the combustion in a wide range of fuel equivalence ratio. The one-sdimensional analysis method was used to analyze the main characteristics of the model. The two-stage fuel injection should have better performance in increasing the chemical reaction rate in the first cavity region