Numerical Study of a Solar Collector Equipped With a Finned Tube Network

Abstract

This research presents a numerical study using Computational Fluid Dynamics (CFD) to analyze the performance of a flat plate solar collector equipped with a finned spiral tube network. The ANSYS Workbench (CFX) software was used to solve the Navier-Stokes equations, adopting the finite volume method, along with the Rosseland radiation model and the Boussinesq approximation for buoyancy forces. Eight turbulence models were compared with reference experimental data at four different flow rates. The results showed the Zero equation model is the most accurate and stable across all conditions, recording lowest mean absolute error (0.86 °C for hot water and 0.95 °C for cold), making it most suitable for simulation in presence of bends and fins. Meanwhile, the k-ε model with the Kato Launder correction was accurate at one flow rate (0.036 kg/s) and showed unstable behavior at higher flow rates, while RSM models failed despite their computational cost. The dimensionless relationships revealed the existence of an optimal flow rate (~0.09981 kg/s) for maximizing thermal performance against pumping power consumption. It is recommended to avoid standard k-ε model and RSM models without prior calibration, and determine the optimal flow rate according to project requirements.