Comparison of Analytical and Numerical Models for Point to Ring Electro-Hydrodynamic Flow

TL;DR

This paper compares analytical, numerical, and experimental approaches to modeling electrohydrodynamic flow in a point-to-ring corona setup, highlighting the influence of electric forces versus inertial effects on flow behavior.

Contribution

It introduces a multiphysics numerical model and compares it with analytical and experimental results, providing insights into flow regimes governed by a nondimensional electric-inertia parameter.

Findings

Electric force dominates flow when X > 1.

Flow resembles pipe flow when X << 1.

Numerical and analytical models agree with experiments.

Abstract

An electrohydrodynamic (EHD) flow in a point-to-ring corona configuration is investigated experimentally, analytically and via a multiphysics numerical model. The interaction between the accelerated ions and the neutral gas molecules is modeled as an external body force in the Navier-Stokes equation (NSE). The gas flow characteristics are solved from conservation principles with spectral methods. The analytical and numerical simulation results are compared against experimental measurements of the cathode voltage, ion concentration, and velocity profiles. A nondimensional parameter, X, is formulated as the ratio of the local electric force to the inertial term in the NSE. In the region of X > 1, the electric force dominates the flow dynamics, while in the X << 1 region, the balance of viscous and inertial terms yields traditional pipe flow characteristics.