Velocity-Field Measurements of an Axisymmetric Separated Flow Subjected to Amplitude-Modulated Excitation (Paperback) (ISBN-13: 9781289147617)

Active flow control was applied at the point of separation of an axisymmetric, backward-facing-step flow. The control was implemented by employing a Helmholtz resonator that was externally driven by an amplitude-modulated, acoustic disturbance from a speaker located upstream of the wind tunnel. The velocity field of the separating/reattaching flow region downstream of the step was characterized using hotwire velocity measurements with and without flow control. Conventional statistics of the data reveal that the separating/reattaching flow is affected by the imposed forcing. Triple decomposition along with conditional averaging was used to distinguish periodic disturbances from random turbulence in the fluctuating velocity component. A significant outcome of the present study is that it demonstrates that amplitude-modulated forcing of the separated flow alters the flow in the same manner as the more conventional method of periodic excitation.

Author: Nasa Technical Reports Server (Ntrs),Barry James Trosin
ISBN-10: 1289147612
ISBN-13: 9781289147617
Publisher: Bibliogov
Language: English
Published: 06/28/2013
Pages: 114
Format: Paperback
Weight: 0.48lbs
Size: 9.69h x 7.44w x 0.24d