基于激光吸收光谱层析技术的超燃冲压发动机氢气引导煤油燃烧过程分析

Analysis of Kerosene Combustion with Pilot Hydrogen in Scramjet Based on Tomography Absorption Spectroscopy

关键词:  超燃冲压发动机  引导点火  激光吸收光谱  吸收光谱层析  发动机测量

Key words:  Scramjet  Pilot ignition  Laser absorption spectroscopy  Tomography absorption spectroscopy  Engine measurement

摘要:

为了解超燃冲压发动机引导点火过程中燃烧流场截面参数分布特征和传播规律，利用激光吸收光谱技术对氢气引导煤油燃烧过程进行测量和分析。在约200ms的引导燃烧过程中，激光吸收光谱层析测量系统对流场截面温度二维分布进行了全程的测量，时间分辨率为1ms。对于测量结果，重点分析了氢气加注、上壁面煤油加注和下壁面煤油加注三个关键阶段的流场变化规律。分析结果表明，在本论文试验所采用的引导点火方式中，火焰在上下壁面之间的传播速度约为15m/s，当煤油燃烧时，流场截面具有较强的非均匀性，高温区域集中在煤油喷注口附近，最高温度达到2500K以上。研究表明，激光吸收光谱层析技术可以为超燃冲压发动机点火过程研究提供丰富且有效的流场截面参数分布信息。

Abstract:

In order to understand the parameter distribution and propagation characteristics of the flow field on cross-section during the pilot ignition in the scramjet， laser absorption spectroscopy was used to measure and analyze the process of kerosene combustion with pilot hydrogen. During the pilot ignition of about 200ms， the 2D temperature distribution of the flow field on cross-section was measured by the system of tomography absorption spectroscopy with the time resolution of 1ms. For the measurement results， the analysis of the flow field changes was focused on three key stages： hydrogen injection， kerosene injection on the upper wall and kerosene injection on the lower wall. The results show that in the pilot ignition mode adopted in this paper， the flame propagation velocity between the upper and lower walls is about 15m/s. When kerosene is ignited， the flow field has a strong non-uniformity， and the high temperature area is concentrated near the kerosene nozzle with maximum temperature above 2500K. It is verified that tomography absorption spectroscopy can provide rich and effective parameter distribution information of the flow field cross-section for the ignition research of the scramjet.