CFD-Based Study on Thermal and Fluid Flow Dynamics Due to Miller Teeth Shaped Ribs Over Absorber Plate of Solar Air Collector

Abstract

Artificial roughness over absorber plate is proven to be a successful technique to enhance the thermal performance of a solar air collector. In the present computational study, a unique shape of repeated rib similar to the shape of miller teeth is considered as artificial roughness over absorber plate to augment thermal efficiency of a solar air collector. In order to assess the overall efficiency, thermo-hydraulic performance factor at different operating parameters is analysed which considers thermal as well as hydraulic performance. Simulation is done using ANSYS FLUENT (ver. 18.1) and is encompassed with Reynolds number range of 3800–18000, relative pitch ratio (P/e) of 7.14–35.7 and relative roughness height (e/D) of 0.021–0.042. The effect of different roughness height and roughness pitch of miller teeth shaped rib on the heat transfer and fluid flow characteristics of a solar air collector is analysed and detail justification is given using different contours derived.