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

这项研究具有混合评估和混合增强的两个部分。首先，进行了一项实验研究，以确认超音速混合条件的时间序列评估的有效性，通过在白金线上使用催化反应。将气态氢注入喷射器中的超音速自由流（马赫1.81）。使用具有铂金线和参考线（镍线）的W型探针评估超音速混合的时间序列条件。评估是通过简单地测量每个电路提供的每种电力来完成的，从而使电线的温度保持恒定。专门为PT电线提供的电力取决于催化热量释放速率（给出氢浓度）和流动转化。指ni线取决于流量转换。结果表明，在混合时，这些电力之间的相关系数增加了。还对氦，空气和无次级I进行了研究……与氢注射案例相比，更多的态度。结果表明，可以通过使用此评估来衡量空气中的超音速混合层或湍流的连贯运动的时间序列行为。对于超音速混合增强，实验表明，大规模流向涡流似乎是最有利的，例如，FFT光质量5均显示了FFT光谱的分析。功率定律表明，出现流向涡流的崩溃是为了产生高度混合能力的小规模湍流涡流。本研究通过使用PIV，Schlieren可视化，热线接种仪和CFD检查了流涡流的分解过程。实验结果表明，在涡旋雷诺数reγ=γ/v = 1.3×10^4或更多的情况下，流向涡流到小规模的湍流中，并且流向涡流上的横向结构参与了其崩溃过程。从计算分析中，坡道的剪切层的振荡可能使流向涡流不稳定并导致其崩溃。较少的