Performance improvement of air-based solar photovoltaic/thermal collectors using wavy channels

The rise in the temperature of photovoltaic (PV) cells leads to a great reduction in their power output; therefore, having a cooling mechanism is critically important to keep the cells of practical benefit in hot climates. The use of wavy surfaces for effective cooling of PV cells seems very promising due to an increased turbulence intensity, generating secondary flows, and improved mixing fluid flows, and has never been studied before. Thus, this study numerically examines the impact of wavy channels with different wavelength (& lambda;), amplitude (& alpha;) ratios, and the Reynolds number to reach an optimal geometry for the wavy channel utilized in PV/T collectors using ANSYS CFX. For this purpose, the Reynolds-averaged Navier-stokes equations are applied and the SST k-& omega; turbulent model is utilized. The results prove the strong impact of the wavy channels where a channel with wavelength & amplitude ratios of 0.1 and 1 has the most increase in the overall efficiency by 20.41% enhancement compared to conventional collectors. In addition, the highest increase in the Nusselt number is 69.7% at & lambda; = 2 and & alpha; = 0.2 compared with the smooth channel. At & alpha; = 0.3 and & lambda; = 3, the electrical efficiency can be enhanced by up to 1.66% at Re = 40,000.