Fluid flow mixing for heat transfer enhancement in communicating converging and diverging channels

Abstract

Under the assumptions of two dimensional, viscous, imcompressible, fully developed and laminar flow condition flow and heat transfer in communicating converging diverging channel is numerically analysed. Periodic boundary condition is applied to inlet and exit of computational domain, and symmetry boundary condition is applied to axises. Momentum, continuity and energy equations are solved numerically using Fluent computer program which is based on finite volume method. In the first part of the study, parallel plate channel is considered and obtained results were compared with the well-known values available in the literature for the convective heat transfer in channels. In the second part, for a given Reynolds number; effect of angle on pressure drop and enhancement of heat transfer are investigated. Mixing of the flow in this channel is illustrated and discussed for different parameters of the channel geometry and Reynolds numbers. It is shown for Reynolds number Re=100, that for a plate angle of 20°, maximum mixing occurs. Mixing flow rate can be high as 25% of the main flow rate. The enhancement of heat transfer is no to high. But from experimental results it is expected high heat transfer ratios at much higher Reynolds number. © 2014, Begell House Inc. All rights reserved.