Study of Turbulent Flow and Heat Transfer Over a Backward Facing Step Under Impingement Cooling

  • Khudheyer S. Mushatet University of Thi qar \College of Engineering,Nassiriya, Iraq
Keywords: Impingement Cooling, Backward-Facing, Turbulent Flow

Abstract

Computations are presented to study the turbulent flow and heat transfer over a channel
backward-facing step under impingement cooling. The problem was simulated for different
parameters, such as the number of impinging jets, contraction ratio, size of jets, and jet and
channel Reynolds numbers. The contraction ratio had the values 0.25, 0.35 and 0.5. The
impinging jets were normal to the cross-channel flow. A control volume approach using
staggered grid techniques was considered to integrate the continuity, fully elliptic NavierStockes and energy equations. A computer program was developed, and the SIMPLE
algorithm was employed to determine the existence of coupling between the continuity and
Navier-Stockes equations. The effect of turbulence was modelled using a k-ε model while the
wall functions laws were used to treat the regions near the solid walls. The presented results
show that the strength and size of recirculation regions near the reattachment region just after
the backward-facing step increase as the contraction ratio increases. Also, the results show
that the size of jets, number of jets, and jet and channel Reynolds numbers have a significant
effect on the flow field, turbulent kinetic energy and variation of the Nusselt number
Published
2019-04-27
Section
Articles