Active Flow Control: Numerical Experiments

Aerospace and Mechanical Engineering Department
University of Arizona

Abstract-
Active Flow Control is becoming more and more a viable tool for modifying flows for many practical applications. "Active Flow Control" typically refers to the use of time-dependent (often periodic) disturbances that are introduced into the flow field by so-called "actuators". Examples for which active flow control proved to be most promising are control of separation, mixing, combustion etc. From past demonstrations of active flow control, it appears that the success of active control strategies is greatest when hydrodynamic instability mechanisms of the underlying base flow can be exploited.

Direct Numerical Simulations (DNS) are a highly suitable tool for investigating hydrodynamic instability mechanisms as demonstrated by the numerous successful simulations of laminar-turbulent transition. Therefore, numerical simulations should also be useful for investigating active flow control. In particular, numerical simulations should help to uncover some of the fundamental mechanisms that are responsible for the often puzzling results when flows are periodically forced. Further, "numerical experiments" of active control strategies may be carried out which, at present, may be too difficult or too expensive to perform in physical laboratory experiments.

In this presentation several such numerical experiments will be discussed. They are all based on numerical solutions of the complete Navier-Stokes equations. The examples presented are for a wide range of flow geometries and flow regimes, from low subsonic (incompressible) to supersonic speeds.

GALCIT Home Page

Fluids Seminar Page