Computational Study of Flow and Heat Transfer in a Sudden Expansion Channel with Inclined Obstacles

Abstract

The laminar flow through an obstacled sudden expansion channel is numerically investigated.
Rectangular adiabatic inclined obstacles mounted behind the expansion region on the upper
and lower wall of the channel were used. The effects of obstacles inclination angle, obstacles
length, obstacles thickness and the number of obstacles on the flow and thermal fields for
different Reynolds number and expansion ratio were examined. The angle of obstacles
inclination was taken in the direction of streamwise flow and ranged from 30° to 90°. Three
values of expansion ratio(ER=H/h) equal to 1.5, 1.75 and 2 were used. The choice of values
of Reynolds number takes the consideration of symmetry state. The body fitted coordinates
system is used to transfer the considered physical problem to computational domain in order
to treat the complexity arising from applicable the boundary conditions near the inclined
obstacles. The governing stream-vorticity equations expressed in generalized coordinates
system were transformed to algebraic equations by using finite difference method. The
solution of these equations was done by iteration method. The obtained results showed that
there is a significant effect of obstacles angle on the hydrodynamic characteristics. The
performed tests of the present results with related published results showed that there is an
acceptable agreement.