Control of flows around a circular cylinder: suppression of oscillatory lift force

The flow past a circular cylinder under continuous and pulsed electromagnet ic forces (or the Lorentz force) is investigated. The Lorentz force is appl ied locally on the cylinder surface in the region of 70-130 degrees from th e stagnation point along the cylinder circumference in both upper and lower surfaces. The experiment is conducted to obtain the force measurement and the visualization of the flow around the circular cylinder on which a circu mferential Lorentz force tangential to the cylinder surface is applied. It was found that both continuous and pulsed Lorentz forces have a significant effect on the flow behaviors around and behind the cylinder as well as on the drag and lift forces acting on the cylinder. Natural seawater is used f or the working fluid and the induction effect can be neglected due to the l ow flow speed and the Lorentz force is found to be linearly proportional to the applied magnetic field and electric current strength within the condit ion of the present investigation. (C) 2001 Published by The Japan Society o f Fluid Mechanics and Elsevier Science B.V. All rights reserved.