Plasma virtual-roughness elements for cross-flow instability control

Choi, Kwing-So; Kim, Jung-Hoon

Abstract

Recent experiments and numerical simulations demonstrated that discrete roughness elements can be used to control cross-flow instability over a swept wing. Here, the application of this passive technique requires a row of thin cylindrical elements of a few microns high immediately downstream of the leading edge to excite the subcritical modes of cross-flow instability. By properly choosing the spanwise spacing of these roughness elements, one can suppress the growth of most unstable modes, thereby delay transition. However, this passive technique of controlling cross-flow instability is very sensitive to the size (diameter and height), shape and location of discrete roughness. To mimic the discrete roughness elements and to be able to adjust the roughness parameters dynamically, virtual roughness elements based on dielectric-barrier-discharge plasma actuators have been developed and tested. In this paper, we show the plasma-induced flow field of several different prototype virtual-roughness elements for cross-flow instability control, by describing the mechanisms of vortex generation from the virtual roughness elements through an interaction with the incoming laminar boundary layer.

Citation

Choi, K., & Kim, J. (2018). Plasma virtual-roughness elements for cross-flow instability control. Experiments in Fluids, 59, Article 159. https://doi.org/10.1007/s00348-018-2609-x

• Journal Article Type: Article
• Acceptance Date: Sep 1, 2018
• Online Publication Date: Oct 1, 2018
• Publication Date: Oct 1, 2018
• Deposit Date: Sep 24, 2018
• Publicly Available Date: Oct 2, 2019
• Journal: Experiments in fluids
• Print ISSN: 0723-4864
• Electronic ISSN: 1432-1114
• Publisher: Springer Publishing Company
• Peer Reviewed: Peer Reviewed
• Volume: 59
• Article Number: 159
• DOI: https://doi.org/10.1007/s00348-018-2609-x
• Keywords: Plasma actuators; Cross-flow instability; Boundary layers; Roughness elements
• Public URL: https://nottingham-repository.worktribe.com/output/1128384
• Publisher URL: http://link-springer-com-443.webvpn.jxutcm.edu.cn/article/10.1007/s00348-018-2609-x