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Study of Transition in Unsteady Boundary Layr induced by Propagating Compression Wave Using Laser Differential Interferometry

激光微分干涉法研究压缩波传播引起的非定常边界层转变

基本信息

批准号：
05650166
负责人：
AOKI Toshiyuki
金额：
$ 1.6万
依托单位：
KYUSHU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05650166/
关键词：
Compression Wave Laser Differential Interferometry Unsteady Boundary Layr Transition High Speed Train

项目摘要

1. The first project was carried out to develop an open-ended shock tube with a fast opening gate valve instead of a diaphragm. The results show that the opening time of a gate valve decreases with an increasing the initial pressure of the actuating chamber.2. The strength, maximum rate of pressure rise and length of wavefront are strongly dependent on the initial pressure of the actuating chamber and the opening speed of a gate valve.3. The second project was carried out to develop a laser differential interferometry method using Wollaston prisms. The sensitivity was sufficiently high to record the density variations by compression waves.4. The measurements of the time-dependent profiles gave detailed information on the process of formation of the unsteady boundary layr induced by propagating compression wave in a constant-area duct.5. The third project was carried out to investigate experimentally and numerically the attenuation of a compression wave. The experimental data were compared with the numerical results by TVD scheme, which takes into account a fluid friction for a transient duct flow.6. It was shown that the attenuation and distortion rates are strongly dependent on a fluid friction term for unsteady laminar or turbulent flow.7. The final project was carried out to investigate experimentally the transition of unsteady boundary layr. The experimental data were compared with the theoretical results for a weak shock wave.8. It was found that the laminar-to-turbulent transition in unsteady boundary layr flow, which describes the density profiles at strength of the initial compression wave from 9kPa, exists.

1. 第一个项目是开发一种带有快速开启闸阀的开放式激波管，而不是膜片。结果表明：闸阀开启时间随执行腔初始压力的增大而减小；压力的强度、最大压力上升速率和波前长度在很大程度上取决于执行腔的初始压力和闸阀的开启速度。第二个项目是利用沃拉斯顿棱镜开发激光微分干涉测量法。灵敏度足够高，可以记录压缩波的密度变化。对随时间变化的剖面的测量给出了恒定面积管道中压缩波传播引起的非定常边界层形成过程的详细信息。第三个项目进行了实验和数值研究压缩波的衰减。采用考虑瞬态管道流动中流体摩擦的TVD格式，将实验数据与数值结果进行了比较。结果表明，对于非定常层流或湍流，衰减率和畸变率强烈依赖于流体摩擦项。最后进行了非定常边界层转捩的实验研究。在弱激波下，将实验数据与理论结果进行了比较。发现非定常边界层流动中存在层流转湍流的过渡，描述了初始压缩波强度为9kPa时的密度分布。