Numerical Analysis of Solar Collector Absorber Tubes with C- shaped Roughness for Enhanced Heat Transfer

Department of Mechanical Engineering, College of Science & Technology, Royal University of Bhutan, 21101 Phuentsholing, Bhutan

^* Corresponding author: agarwala.cst@rub.edu.bt

Abstract

Solar collector absorber tubes perform a significant function in solar power devices that concentrate the solar energy into a single cylindrical absorber tube. Characteristically, this type of tube is covered with a smooth surface. The purpose of this study is to simulate the convectional behaviour of these absorber tubes with the help of numerical calculation methods like Computational Fluid Dynamics (CFD). The collector tube CAD model has been made using the Creo design software and the ANSYS CFX software is used for the CFD simulations corresponding to the three mass_flow rates (0.005Kg/s, 0.010Kg/s, and 0.015Kg/s). The heat transfer is improved by tweaking the absorber tube with a C-shaped corrugated roughness profile. The choice of the Shear Stress Transport turbulence (SSTT) model for analysis is justified by its capability to accurately predict both laminar and turbulent flows, which is why it is considered to be suitable for the absorber tube with a cross-sectional shape. Findings demonstrated that the use of C-shaped artificial roughness led to a substantial rise in convective heat transfer, for 6.016% of the thermal conductivity was taken into account. The SST turbulence model verifies its efficacy by predicting the fluid flow patterns across the absorber tubes. This study forms the basis for developing new mechanical efficiency metrics for solar collector absorber tubes, which is significant for solar energy technology development.