脉冲燃烧风洞点式油流技术在压缩拐角流动显示中的应用

Application of Oil Flow Visualization Technique in a Pulse Type High Temperature Wind Tunnel to Visualize

关键词:  脉冲燃烧风洞  油流显示技术  压缩拐角  油流图谱  高超声速进气道

Key words:  Pulse combustion wind tunnel  Oil flow visualization technique  Compression corner  Oil flow pattern  Hypersonic inlet

摘要:

为在脉冲燃烧风洞上应用油流技术，针对该类设备马赫数6条件下气流总温高(可达1650K)、有效试验时间短(约300ms)、小动压条件下显示油“流不动”等困难，提供了一种技术解决方案。试验设备为中国空气动力研究与发展中心Φ=600mm脉冲燃烧风洞。采用两个多级压缩楔模拟高超进气道外压缩面，其中三级压缩楔偏转角为6°，7°和8°，两级压缩楔偏转角均为10°。运用高速摄像方法获得了点式图谱的动态变化过程。三级压缩楔8°拐角上游油点在200ms内流过了拐角，并向下游移动了足够长度，可判断该拐角处气流不产生分离。两级压缩楔油流结果则显示风洞尾气会显著改变图谱分布。

Abstract:

In order to apply oil flow visualization technique in Pulse Combustion Wind Tunnel，a technique scheme is offered，where high total temperature (up to 1650K)，short valid test duration (about 300ms)，and low dynamic pressure (oil flow moves slowly) are encountered. The experiment was carried out in Φ=600mm Pulse Combustion Wind Tunnel of China Aerodynamics Research and Development Center (CARDC). Two multi-stage compression ramps were selected as the test models instead of the hypersonic inlet compression surfaces，one was a three-stage compression ramp with the deflextion angle of 6°，7°and 8°，another one was a two-stage compression ramp with the deflextion angle of both 10°. The stretch process of the upstream oil dots of the 8° deflextion angle corner was recorded by a high speed camera，in which the oil dots moved across the corner and extended downstream with a considerable distance in 200ms，indicating that the corner flow is not separated. The oil flow patterns of the two-stage compression ramp show the exhaust gas of wind tunnel can change the graphs notably. It is necessary to analyze the field structure according to the graphs taken in the valid test duration in these pulse type facilities.