Closed-Loop Control of Vortex Shedding by Means of Lorentz Force
Abstract
In many applications, vortex shedding past a bluff body is undesirable, as it generates a significant increase in drag and an oscillating lift force on the body leading to cross-stream structural vibrations. The goal of the present work is to derive a closed-loop control algorithm for suppressing vortex shedding from a circular cylinder in a conducting fluid, by applying a Lorentz force generated by electrodes and magnets alternatively arranged on the cylinder surface. In a weakly conducting fluid such as seawater, the Lorentz force is tangential to the surface of the cylinder, oriented in the direction of the incoming flow. A novel analytical expression of the Lorentz force is derived from the electro-magnetic problem by means of series expansions and then used for the control of vortex shedding in numerical simulations. Specifically, a closed-loop control algorithm utilizing a single point sensor on the cylinder is derived using the iterative searching method for determining the appropriate magnitude of the Lorentz force at every time. Numerical simulations based on a two-dimensional Navier-Stokes equations show that the scheme is successful at suppressing vortex shedding at the Reynolds number values Re = 100 and 200.
- Publication:
-
APS Division of Fluid Dynamics Meeting Abstracts
- Pub Date:
- November 2003
- Bibcode:
- 2003APS..DFD.JA005L