Numerical Investigation of Hydrothermal Characteristics in Backward-Facing Step Channel with Obstacles

The present numerical work investigates the forced convection fluid flow through a backward-facing step (BFS) in the channel with obstacles.Three different shapes of obstacles which are circular, square and diamond have been considered to enhance the hydrothermal performance.The finite volume procedure has been utilized to resolve the two-dimensional continuity, energy, and momentum equations.Influence of obstacle sizes (d/H=0.2,0.3, and 0.4) as well as obstacle locations (b/H=2, 3, and 4) on the hydrothermal performance factor, pressure losses, and mean Nusselt number have been analyzed for Reynolds number between 200 and 1000.Results indicate that as the Reynolds number rises, the average pressure losses and Nusselt number rise, well the thermal-hydraulic performance factor decreases.The circular obstacle provided the highest heat transfer enhancement (about 49%) at Re=1000, d/H=0.4,and b/H=2 compared with the baseline case.In addition, the performance factor rises with the reduction in the distance between the obstacles and the step.The best performance factor is around 1.24 which can be obtained utilizing a BFS channel with a circular obstacle at Re=200, d/H=0.4 and b/H=2, making it the optimal setup for applications requiring efficient thermal management with minimal pressure loss penalties.