2014流体所学术报告2

Title: Feedback flow control on unstable flows

不稳定流动的反馈控制

Time: 4:00 PM, July 17 (Thursday), 2014

2014年7月17日

Location：Conference Room of Institute of Fluid Mechanics

流体所会议室

Reporter: Dr. Simon Illingworth

Department of Mechanics, The University of Melbourne

墨尔本大学力学系

Abstract:

Feedback flow control has been investigated for a number of unstable flows including combustion oscillations, compressible cavity resonances and vortex shedding. Many of the early studies of feedback flow control used simple phase-shift controllers that were found by trial-and-error. More recently, the application of linear control theory to fluid flows has been promoted, and there exists great scope for these techniques to be applied to flow resonances. My presentation will focus on model-based feedback control of flow resonances, with application to three systems: combustion instability on a laboratory-scale rig (a Rijke tube); compressible cavity oscillations; and vortex shedding from a circular cylinder at low Reynolds numbers. The presentation will focus in particular on finding low-order models of flow resonances that are useful for feedback control purposes. I will also demonstrate the improvements in performance (i.e. better resonance suppression) and robustness (i.e. control effectiveness over a larger range of operating conditions) that are possible when model-based control techniques are used. For all systems, in addition to demonstrating the efficacy of the feedback controllers, I will also discuss some of the challenges of control.

-------------------------------------------------------------------------------------------------------

Dr. Simon Illingworth is a lecturer in the Department of Mechanical Engineering at the University of Melbourne. He received his Ph.D. from the University of Cambridge, and his M.Eng. in Aeronautical Engineering from the University of Bristol. He was a postdoctoral researcher at the University of Cambridge, and he also held a JSPS research fellowship at Keio University in Japan. Simon Illingworth's research involves applying methods from dynamical systems and control theory to flow instabilities. These methods have been applied to problems in thermoacoustics (combustion oscillations); aeroacoustics (cavity oscillations) and fluid mechanics.