Experimental study and analysis of shock train self-excited oscillation in an isolator with background waves

Hou, Wen-xin, Chang, Jun-tao, Kong, Chen, Bao, Wen and Dala, Laurent (2020) Experimental study and analysis of shock train self-excited oscillation in an isolator with background waves. Journal of Zhejiang University: Science A. ISSN 1673-565X (In Press)

[img] Text
ZUSA-D-20-00042.pdf - Accepted Version
Restricted to Repository staff only until 15 July 2021.

Download (2MB) | Request a copy

Abstract

A study of shock train self-excited oscillation in an isolator with background waves was implemented through a wind tunnel experiment. Dynamic pressure data were captured by high-frequency pressure measurements and the flow field was recorded by the high-speed Schlieren technique. The shock train structure was mostly asymmetrical during self-excited oscillation, regardless of its oscillation mode. We found that the pressure discontinuity caused by background waves was responsible for the asymmetry. On the wall where the pressure at the leading edge of the shock train was lower, a large separation region formed and the shock train deflected toward to the other wall. The oscillation mode of the shock train was related to the change of wall pressure in the oscillation range of its leading edge. The oscillation range and oscillation intensity of the shock train leading edge were affected by the wall pressure gradient induced by background waves. When located in a negative pressure gradient region, the oscillation of the leading edge strengthened; when located in a positive pressure gradient region, the oscillation weakened. To find out the cause of self-excited oscillation, correlation and phase analyses were performed. The results indicated that the instability of the separation region induced by the leading shock was the source of perturbation that caused self-excited oscillation, regardless of the oscillation mode of the shock train.

Item Type: Article
Uncontrolled Keywords: Self-excited oscillation, Background waves, Asymmetrical structure, Source of perturbation
Subjects: H300 Mechanical Engineering
H800 Chemical, Process and Energy Engineering
Department: Faculties > Engineering and Environment > Mechanical and Construction Engineering
Depositing User: Elena Carlaw
Date Deposited: 21 Jul 2020 09:06
Last Modified: 21 Jul 2020 09:15
URI: http://nrl.northumbria.ac.uk/id/eprint/43836

Actions (login required)

View Item View Item

Downloads

Downloads per month over past year

View more statistics