Heat Transfer and Fluid Flow behaviours of a Square Twisted Micro-Channel

Abstract

The heat transfer and pressure drop analysis of twisted square micro-channel is studied numerically for Reynolds number (Re) ranging from 10 to 250. The laminar flow model is used for formulation in Ansys fluent 15.0, since the flow is laminar. The governing equations are solved with a finite-volume-based numerical method. A three-dimensional non uniform grid was generated, in order to critically examine the flow and heat transfer. The effects of aspect ratio and twist ratio on the Nusselt number and friction factor are investigated. It is found that the twisted geometry of the channel evidently enhance heat transfer by generating longitudinal vortices, which strengthen flow mixing. Such small vortices also upsurge the turbulent kinetic energy (TKE) and decrease thickness of the boundary layer, which lowers local temperature nearby the target surface. Computational results show that the simulation with twisted micro-channel geometry considerably better than the case with straight micro-channel with respect to heat transfer performance.