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International Journal of Aerospace Engineering
Volume 2018, Article ID 7234706, 13 pages
https://doi.org/10.1155/2018/7234706
Research Article

Receptivity of the Boundary Layer over a Blunt Wedge with Distributed Roughness at Mach 6

1College of Aerospace and Civil Engineering, Harbin Engineering University, Harbin 150001, China
2China Academy of Space Technology, Beijing 100094, China

Correspondence should be addressed to Xiaojun Tang; moc.anis@78gnatnujoaix

Received 8 December 2017; Accepted 28 March 2018; Published 29 April 2018

Academic Editor: William W. Liou

Copyright © 2018 Zhenqing Wang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

A hypersonic flow field over a blunt wedge with or without roughness is simulated by a direct numerical simulation method. The effect of isolated and distributed roughnesses on the steady and unsteady hypersonic flow field and boundary layer is analyzed. The shape of roughness is controlled by cubic polynomial. The evolution of disturbance waves caused by slow acoustic wave in the boundary layer is investigated by fast Fourier spectrum analysis. The results show that there is a great influence of roughness on the evolution of disturbance waves in the hypersonic boundary layer. The disturbance waves are promoted in the upstream-half region of roughness while suppressed in the downstream-half region of roughness. There is always a mode competition among different modes both in the temporal domain and in the frequency domain in the boundary layer, and mode competition is affected by roughness. The location of the dominant mode which is changed to a second-order harmonic mode from the fundamental mode moves upstream. The vortices caused by roughness also impact the evolution of disturbance waves in the boundary layer. The fundamental mode is suppressed in the vortex region while other harmonic modes are promoted.