Effect of Perforation Size to Perforation Spacing on Heat Transfer in Laterally Perforated-Finned Heat Sinks

Thermo-fluid characteristics of laterally perforated-finned heat sinks (LA-PFHSs) are investigated through experiments in laminar forced convection flows, in order to understand the key parameters affecting thermo-fluid transport phenomena and, in turn, parameters that play important roles to correlate heat transfer coefficients of LA-PFHSs. For this purpose, the Nusselt numbers of the LA-PFHSs are calculated using the well-accepted technique in the literature that was proposed to model Nusselt numbers of the slotted-finned heat sinks. Square cross sectional perforations at three different sizes are distributed along the length of the LA-PFHSs in inline configurations. Each perforation size is tested under five different porosities. The accuracy of the experiments are validated by comparing the pressure drops and Nusselt numbers of the imperforated heat sink against the correlated values obtained from the well-accepted correlations in the literature. Results indicate that the flow interactions over the perforations with each other are dominant mechanisms that affect transport phenomena in LA-PFHSs. The flow interactions with each other are proportional to the ratio of the perforation size to the solid distance between two-adjacent perforations. Therefore, this dimensionless geometrical parameter is found as the key parameter affecting thermo-fluid transport phenomena and, in turn, correlations to predict heat transfer coefficients of LA-PFHSs. At the end, suggestions are provided to develop physics-based correlations to predict heat transfer coefficients of LA-PFHSs through future research.