Practical approaches to assess thermal performance of a finned heat sink prototype for low concentration photovoltaics (LCPV) systems: Analytical correlations vs CFD modelling

The performance of a low-cost extruded heat sink prototype for a Low Concentration Photovoltaics system studied using various analytical correlations and CFD simulations. An experimental test, with temperatu, measurements at different monitoring points of heat sink surface, was carried out in order to select the mo appropriate approach. Large deviations (of up to 20*C) in the estimation of base plate temperature from co relations were found when compared to experimental results, probably due to the specific geometry cha acteristics of the heat sink, with variable fin thickness and high fin length. Furthermore, discrepancies of up 48% have been found among the different correlations. The numerical CFD results of temperature at monitor! points and at the base plate showed relative errors of about 1%, which were at least 15 times smaller than tl results given by analytical correlations. Also, numerical simulations allowed the identification of stagnatic zones due to the great length of the heat sink and characteristic air flow patterns, which help to explain i performance under different operating conditions. Thus, results showed that multiple chimney flow pattern ar air stagnation zones seem to disappear for inclination angles greater than 30.