Heat Transfer Enhancement by Imposed Pulsation in a Channel With Sudden Expansion

Abstract

A numerical investigation of laminar pulsating flows in a channel with sudden expansion in the cross section has been performed by solving two dimensional Navier-Stokes and energy equations for an incompressible fluid. A sinusoidal pulsation has been imposed on the axial velocity at the inlet. Results show that the flow field symmetry at the channel axis vanishes at even a Reynolds number of 100. The time averaged Nusselt number of pulsating flow increases sharply over the nonpulsating flow in the Reynolds number range of 400 and 500. The time averaged Nusselt number on the two walls can be different.