Numerical evaluation of using micropolar fluid model for EHD-induced natural convection heat transfer through a rectangular enclosure

Abstract

Using turbulent models for electrohydrodynamic (EHD) induced flow modeling in hydraulically laminar flow ranges has been always questionable. This study is concerned with EHD cases in natural convection heat transfer within an enclosure. Here, the micropolar model was engaged and became the main motivation of the current study as an alternative approach for the fluid dynamic behavior. The numerical investigations were performed to study the effect of the various key parameters: the applied voltage, Rayleigh number, and the gap size of the electrodes. The main challenge of using the micropolar model is the evaluation of the adequate material parameter (κω/μ); all the presented numerical investigations conducted to find the proper material parameter for various flow conditions. All cases were carried out for a two-dimensional approach with a non-uniform structured grid, which is used by a finite volume algorithm to solve the EHD natural convection governing equations. Comparing the results of the micropolar approach with those obtained from the turbulent standard k-ε model reveals that the micropolar model can be an appropriate candidate to simulate the EHD natural convection flow instead of fully turbulent models. The results depicted that by increasing Rayleigh number and the applied voltage, the discrepancy between the results of the micropolar and the standard k-ε model increases.