Effect of Ground Arrangements on Swirling Flow in a Rectangular Duct Subjected to Electrohydrodynamic Effects

Abstract

This study presents a numerical analysis of electric fields distribution, characteristics of swirling flow and effect of inlet velocity (u0) from two ground arrangements, i.e., wire-to-wire (WW) and wire-to-plate (WP) in a rectangular duct subjected to electrohydrodynamic. In both arrangements, location of an electrode wire, which is suspended from the upper wall of the duct, is initially located at the centerline of the rectangular duct, and ground is fixed on the bottom wall. In WW, position of electrode is varied in the vertical direction, while in WP, they are varied both in the vertical and horizontal directions. Electrical voltage of 20 kV is applied and inlet velocity in range of 0.3 – 1 m/s is selected. The numerical results show that electric fields distributions from both arrangements are quite different. These results cause the characteristics of swirling flows to appear differently. In both arrangements the maximum electric fields intensity are not different for each identical gap value. When the gap is closer, electric fields increase significantly. When inlet velocity of air is increased, the strength of swirling flow is decreased because inertial force is superior to the electric body force.

Flow control with electrode bank arrangements by electrohydrodynamics force for heat transfer enhancement in a porous medium

“…This is because the electric field ( E ) from Eq. depends on electrical voltage ( V 0 ) so electric field intensity increases with increasing number of electrodes . Furthermore, electric field is independent of inlet velocity and time.…”

“…This is because the inlet velocity of air is increased; the strength of swirling flow is decreased because inertial force is greater than the electric force. It means the Reynolds number is small so the effect of electric force is dominant …”

“…Consequently, it is made clear that the corona wind was caused by the Coulomb force exerted on ions and collisions of ions and neutral molecules of gas. Mechanism of EHD method is presented by Saneewong Na Ayuttaya and colleagues . When electrical voltage is exposed to airflow, the airflow is created by ions generated in the corona discharge near the sharp electrode that drift to the ground.…”

“…For increasing flow, pumping is often cited as a general application which requires ongoing development of microfabricated motors and other actuators. A practical requirement for EHD pumping is the induction of free electric charge in the volume of the fluid to be pumped or on its interface with another material . For spread flow, electrospraying is a method of liquid atomization by electrical forces.…”

“…From previous studies, Saneewong Na Ayuttaya and colleagues were early investigators of swirling flow in 2012. In this study, shear flow was established to appear due to differences in fluid velocity between charged airflow and uncharged airflow.…”