Instantaneous and time-averaged flow structures around a blunt double-cone with or without supersonic film cooling visualized via nano-tracer planar laser scattering

被引：20

作者：

Zhu Yang-Zhu ^{[1
]}

Yi Shi-He ^{[1
]}

He Lin ^{[1
]}

Tian Li-Feng ^{[1
]}

Zhou Yong-Wei ^{[1
]}

机构：

[1] Natl Univ Def Technol, Coll Aerosp Sci & Engn, Changsha 410073, Hunan, Peoples R China

来源：

CHINESE PHYSICS B | 2013年 / 22卷 / 01期

基金：

中国国家自然科学基金;

关键词：

blunt cone; supersonic flow structure; flow visualization; supersonic film cooling; MIXING LAYER; INSTABILITY;

D O I：

10.1088/1674-1056/22/1/014702

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

In a Mach 3.8 wind tunnel, both instantaneous and time-averaged flow structures of different scales around a blunt double-cone with or without supersonic film cooling were visualized via nano-tracer planar laser scattering (NPLS), which has a high spatiotemporal resolution. Three experimental cases with different injection mass flux rates were carried out. Many typical flow structures were clearly shown, such as shock waves, expansion fans, shear layers, mixing layers, and turbulent boundary layers. The analysis of two NPLS images with an interval of 5 mu s revealed the temporal evolution characteristics of flow structures. With matched pressures, the laminar length of the mixing layer was longer than that in the case with a larger mass flux rate, but the full covered region was shorter. Structures like K-H (Kelvin-Helmholtz) vortices were clearly seen in both flows. Without injection, the flow was similar to the supersonic flow over a backward-facing step, and the structures were relatively simpler, and there was a longer laminar region. Large scale structures such as hairpin vortices were visualized. In addition, the results were compared in part with the schlieren images captured by others under similar conditions.

引用

页数：6