Clarification and Application of Turbulent Mixing for Hydrogen Air Supersonic Mixing

氢气-空气超音速混合湍流混合的澄清及应用

基本信息

批准号：
17560694
负责人：
ARAI Takakage
金额：
$ 2.24万
依托单位：
Osaka Prefecture University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17560694/
关键词：
Supersonic Mixing Boundary Layer Transition Scramjet Streamwise Vortices Catalytic Reaction PIV Vortex Breakdown シュリーレン法

项目摘要

This research has two parts of the mixing evaluation and mixing enhancement.First, an experimental study was carried out to confirm the validity of time series evaluation of supersonic mixing condition by using catalytic reaction on a platinum wire. Gaseous hydrogen was injected into supersonic free-stream (Mach 1.81) from injector. Time series condition of supersonic mixing was evaluated by using W-type probe which has a platinum wire and reference wire (nickel wire). The evaluation was done by simultaneously measuring each electric power supplied by each electric circuit which kept the temperature of wire constant. Specifically supplied electric power to Pt wire depended on catalytic heat release rate (giving hydrogen concentration) and flow convection. Meanwhile that to Ni wire depended on flow convection. The result showed that correlation coefficient between these electric powers increased when mixing developed. Investigations were also conducted for helium, air and no secondary i … More njectant cases to compare with the hydrogen injectant case. The results indicated that it was possible to measure the time-series behavior of air-hydrogen supersonic mixing layer or coherent motion of turbulence by using this evaluation.Second, for supersonic mixing enhancement, experiments suggested that large scale streamwise vortices seemed to be the most advantageous, for example, FFT spectrum analysis of mass flux fluctuations showed that the power spectrum partly follows Kolmogorov's -5/3 power law, indicating that the breakdown of streamwise vortices occurred to generate small scale turbulent eddies of high mixing power. The present study examined the breakdown process of streamwise vortices by using PIV, schlieren visualization, hot-wire anemometer and CFD. The experimental results showed that the breakdown of streamwise vortices into small scale turbulence occured at the vortex Reynolds number ReΓ=Γ/v=1.3×10^4 or more, and that the lateral structure on streamewise vortices took a part in its breakdown process. From the computational analysis, the oscillation of shear layer from ramp could make the streamwise vortices unstable and cause its breakdown. Less

这项研究具有混合效果的两个部分。首先，进行了一项实验研究，以确认在铂金属丝上使用催化反应对超音速混合条件的评估使用具有铂金线和参考的W型（镍线）来评估内部混合。同时。结合增强，经验表明，大型流向矫正器似乎是最有利的，例如，FFT频谱分析的质量通量通量分析表明，特殊的功率部分部分是s kolmogorov's-5/3功率定律，表明流媒体的崩溃是出现在流媒体中的。高混合能力研究了使用PIV，Schlieren可视化，热线肛门表和CFD的分解过程。 /γ/γ/γ/γv = 1.3×10^4或更多，而流层涡旋上的横向结构则来自其分解过程。不稳定和原因是崩溃。