Numerical Investigation of Corrugated Channel with Backward-Facing Step in Terms of Fluid Flow and Heat Transfer

Abstract

In this study, the turbulent fluid flow and heat transfer through a backward-facing step connected by various triangles to a corrugated wall were numerically investigated. The governing equation was solved with Ansys Fluent, a CFD (Computational Fluid Dynamic) application that provides solutions using the Finite Volume Method (FVM). The working channel was considered with the step length H and an expansion ratio of 2. While the main channel geometry has a straight bottom surface, the compared channel geometry has a triangular bottom surface with various step lengths (p = 5 mm, p = 10 mm, and p = 15 mm) at a constant amplitude height (5 mm), and a heat flux of 4 kW/m2 was applied to this surface. The Reynolds number Re was studied in the range of 5000 to 20000. The Performance Evaluation Criterion (PEC) values, which are a function of the Nusselt number Nu and the skin friction, are calculated. As a result, while all the surfaces increase the heat transfer, the highest PEC values are obtained at Re = 5 × 103 and Re = 104 in the channel with the 10 mm triangular bottom surface and at Re = 1.5 × 104 and Re = 2 × 104 in the channel with the 20 mm triangular bottom surface.