Управление Обтеканием Круглого Цилиндра С Помощью Коронного Разряда

Abstract

In the paper an influence of ion wind caused by positive corona discharge on a bulk motion near a circular cylinder at Reynolds numbers 2400, 3200 was studied. The geometry of the cylinder-wire electrodes was considered for two positions of the active electrode relative to the cylinder: behind the cylinder and two symmetrical wires above and below the cylinder. A direct numerical simulation of electrohydrodynamic problem was performed. The original unipolar model of the corona discharge was used. The impact of a thin jet of ion wind directed from the active electrode to the cylinder on vortex wake behind the cylinder and the drag force was considered. It was shown that when two active electrodes are placed above and below cylinder, the electric wind prevents the formation of the Karman vortex street and also significantly reduces the aerodynamic resistance of cylinder. When the active electrode is located behind the cylinder, the corona discharge and the ion wind lead to the formation and development of large vortices in the wake of the cylinder, which leads to significant fluctuations in the aerodynamic drag. It was shown that corona discharge significantly changes Karman vortex street properties. Specifically with an increase in the voltage to 30 kV, the vortex detachment frequency decreases by 2.5 times, the size of the vortices and the speed of their rotation dramatically grow. The drag force is quasi-periodic, its average value linearly depends on the applied voltage.