Performance estimation of Triangular Solar air heater roughened absorber surface: An experimental and simulation modeling

Abstract

The roughness on the absorber surface can increase the performance of a triangular solar air heater. This paper reveals a comparative study of smooth and rough absorber surfaces with V ribs to improve triangular solar air heater performance. The absorber plate coated with graphene nanoparticles doped into the black paint in both cases. The investigation incorporated rib roughness parameter as P/e = 1.4 for the arrangement and investigated at different parameters of the solar intensity. The roughness effect on friction factor and heat transfer characteristics has been investigated numerically and experimentally. A three-dimensional simulation is conceded out using Ansys 14.5 software and k-ε, RNG turbulence model to solve the governing equation in turbulence case. Using MATLAB optimizable Gaussian process regression (GPR) analysis, create an energy and exergy efficiency analysis prediction model. The experimental results indicate an average 4.93% thermal efficiency increase, and average exergy efficiency increases by 4.41 % to compare smooth plates. The simulation result shows temperature variation inside the duct, which is reduced through the length of the solar air heater. Compared to Reynolds number changes and relative roughness pitch (P/e), V-shaped rib roughness significantly impacts friction factor and heat transfer characteristics. We conclude that better outcomes are obtained after investigating triangular duct designs absorber surface roughness patterns.