Heat Transfer and Fluid Flow Characteristics of a Turbulent Dual Jet Impinging on a Wavy Surface

Abstract

Abstract A simple and effective technique is proposed to enhance the heat transfer rate significantly. The current study deals with the analysis of a fluid flow and thermal characteristics of a turbulent dual jet impinging on a wavy surface. The surface area of the wall has been varied by considering different wavy profiles. The amplitude of the wavy surface is varied between 0.1 and 0.7 with an interval of 0.1. The number of cycles and the offset ratio (OR) are fixed to 10 and 7, respectively, thus, providing a complete parametric analysis of flow characteristics and thermal characteristics of the turbulent dual jet. The decay of maximum streamwise velocity, the variation of bottom wall pressure, and the variation of local heat flux and local Nusselt number have been computed. The variation of the bottom wall temperature for adiabatic wavy wall boundary condition for various amplitudes are also presented in this paper. It is found that the pressure decreases in the recirculation region when the amplitude increases. There is a sudden drop in pressure in the recirculation region when the wavy surface is present as compared with the dual jet with a plane wall surface and this drop goes on increasing as the amplitude increases. The wavy surface provides a favorable condition for the flow which results in the increased flow strength. The increase in the flow strength ultimately enhances the heat transfer rate. But, the increase in heat transfer is not monotonous. The heat transfer rate increases till the amplitude 0.5 thereafter it decreases. A maximum increase of 12% in the heat transfer rate is observed at A = 0.5. It is hoped that the present study opens a new line for the industries which deal with the cooling phenomenon.