Investigation of flow characteristics and heat transfer enhancement of various duct geometries

The aim of this study is to determine the flow characteristics and thermal efficiency in various ducts geometries numerically and experimentally. The whole study has been conducted for Reynolds numbers in the range of 3000≤Re≤6000. Firstly, the effect of aspect ratio, s/H on heat transfer enhancement and on flow structures was aimed to be examined. Therefore, the corrugated duct geometries were designed for three different aspect ratios such as s/H=0.1, 0.2, 0.3 and various phase shift angles, φ of corrugated channels. Thermal efficiency of these geometries were examined numerically in order to optimize the aspect ratio, s/H. Afterwards, experimental studies were conducted in order to identify hydrodynamic structures and verify findings of numerical solution using Particle Image velocimetry (PIV). Throughout the study, three different phase angles, φ=0̊, 90̊ and 180̊, were utilized. Velocity distributions, patterns of streamline and corresponding turbulent statistics were determined experimentally and numerically in order to reveal hydrodynamics and thermal efficiency of the corrugated channel flow. In numerical calculations, standard k-ε turbulent model was utilized. As a result of numerical studies, Nusselt number, Nu friction factor, f and efficiency index, η were calculated for different corrugated channel geometries. Consequently, it was observed that numerical and experimental results were extremely compatible with each other