Effects of the Intrinsic Three-Dimensionalization of Laminar Separation Bubbles on the Amplification of External Disturbances

Abstract: 

The size and behavior of laminar separation bubbles is strongly related to the laminar-to-turbulent transition process that takes place downstream of the separation of the laminar boundary layer. Wind-tunnel experiments and numerical simulations in which external fluctuations are imposed show a clear dominance of instability waves of convective nature in the transition process. On the other hand, stability analysis demonstrate the existence of a self-excited mechanism that introduces a three-dimensionalization of the recirculation region. This paper studies the co-existence of both mechanisms, i.e. how the spanwise modulation of the bubbles can alter the properties of instability waves. It is found that a large convective amplification is induced by the spanwise velocity gradients.

Author: 
Rodriguez, D
Gennaro, E
Publication date: 
September 9, 2018
Publication type: 
Conference Paper
Citation: 
Rodríguez, D., & Gennaro, E. (2018). Effects of the Intrinsic Three-Dimensionalization of Laminar Separation Bubbles on the Amplification of External Disturbances. 31st Congress of the International Council of the Aeronautical Sciences …, Query date: 2024-12-09 21:28:55. https://scholar.google.com/citations?view_op=view_citation&hl=en&user=YmyOoaYAAAAJ&cstart=300&pagesize=100&citation_for_view=YmyOoaYAAAAJ:J6OZcwVsj5AC