The Enhancement Effect of Corona Discharge on Natural Convection Heat Transfer in Triangular Channels

Abstract

A numerical research was conducted to investigate the effect of corona discharge on natural convection heat transfer in a triangular channel. The channel side walls were isothermal, the lower wall was adiabatic, and the fluid was air at the atmospheric pressure. The electric field was generated by a positive corona discharge from a charged wire electrode located at the center of the channel. The governing equations of the electric and flow fields were solved by a finite-volume technique. Three cases were considered: (1) natural convection; (2) corona-induced convection; and (3) combined natural and corona-induced convection. The computations encompassed Rayleigh numbers from 3,737 to 37,377 and applied voltages from 7 to 9 kV in the laminar regime. Computations for the applied voltage of 7.5 kV indicated that the heat transfer was enhanced from Nu/Nu0 = 1.01 to 1.04, or 1–4%, for different values of Ra. The enhancement at Ra = 3,737 and the applied voltage of 7 to 9 kV was Nu/Nu0 = 1.01 to 1.40, or 1–40%.

Experimental Investigation of Natural Convection in Inclined Channel in Presence of Electrostatic Field

“…Their results showed that an increase in heat transfer depends on the number of electrodes and number of waves along the channel. Molki and Harirchian [16] numerically investigated the effect of corona discharge on natural convection heat transfer in a triangular channel. The results showed that the heat transfer was enhanced from 1 -4%, for different Ra values.…”

Experimental investigation on convective heat transfer enhancement by EHD in wire to plate configuration

“…A list of relevant studies using EHD in process engineering applications, dealing with heat transfer enhancement, is presented in Table 1. Many studies deal mainly with natural convection flow [19,21,31,32], and are rarely focused on the forced convection flow. Velkoff and Godfrey [16] reported the first experiments on heat transfer enhancement by ionic winds in the presence of external flows.…”