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Shock Tube Research on Oblique Shock Reflection Over a Dust Layer

粉尘层斜激波反射激波管研究

基本信息

批准号：
01550051
负责人：
ADACHI Takashi
金额：
$ 1.22万
依托单位：
Saitama Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1990
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-01550051/
关键词：
Shock Wave Dust Layer Oblique Shock Reflection Mach Reflection Unsteady Flow

项目摘要

Oblique reflection of a planar shock wave over a dust layer was investigated. Experiments were conducted using a shock tube, and waves were visualized through schlieren method. Angles of incidence and reflection were measured directly from negative films. Incident shock Mach number was fixed at 1.41. Mean diameter of spherical particles deposited on a wedge and depth of the dust layer were 30mum and 0.6mm respectively. Main conclusions are as follows :1. Results were compared with those for two-dimensional guttered wedge, and following points of resemblance were revealed. (1) Unsteady behavior of incidence and reflection shows that the shock reflection over both the dust layer and two-dimensional guttered wedge is essentially unsteady phenomena. (2) Transition from regular to Mach reflection occurs as the incident shock propagates for constant incident shock Mach number and slope of wedge surface. (3) For the specified incident shock Mach number and slope of wedge surface where reflection pattern is Mach type for smooth surface, reflection in both cases remains regular type. This fact can be explained well by a modified two-shock theory taking account of "sink effect" of dust layer.2. Experiments for the dust layer were compared with the modified two-shock theory. It is found that the relative flow velocity just behind the Mach stem or reflection point have a velocity component normal to the dusty surface. The deflection angles are about 4^O -6^O for Mach reflection and 8^O -14^O for regular reflection.

研究了平面激波在尘埃层上的斜反射。利用激波管进行了实验，并通过纹影法对波进行了可视化。入射角和反射角直接从底片上测量。入射激波马赫数固定在1.41。沉积在楔形物上的球形颗粒平均直径为30 μ m，粉尘层深度为0.6mm。主要结论如下：1.结果与二维槽楔的结果进行了比较，并揭示了以下相似之处。(1)非定常入射和反射特性表明，激波在尘埃层和二维槽楔上的反射本质上是非定常现象。(2)当入射激波马赫数和楔面斜率不变时，入射激波传播过程中会发生从规则反射到马赫反射的转变。(3)当入射激波马赫数和楔面斜率一定时，光滑表面的反射模式为马赫型，两种情况下的反射模式均为规则型。这一现象可以用考虑尘埃层“下沉效应”的修正双激波理论来解释.粉尘层的实验进行了比较，与修改后的两个冲击理论。结果表明，在马赫干或反射点后的相对速度有一个垂直于尘埃表面的速度分量。马赫反射的偏转角约为4^0 - 6^0，规则反射的偏转角约为8^0 - 14^0。