Prediction methods for natural convection around hollow hybrid fin heat sinks

This study investigates prediction methods for natural convection around hollow hybrid fin heat sinks (HHFHSs). The HHFHS is the staggered array of hollow pin fins concatenated with radially-placed plate fins. 3-D computational thermal models have been generated using a commercial CFD software package and used to develop correlations to predict Nusselt numbers around HHFHSs. Nearly hundred cases under various parametric conditions have been calculated to obtain a broad range of thermal data. Correlations for Nusselt numbers have been obtained by considering their dependence on Rayleigh number, internal and external diameters, and fin height. The correlations are seen to reasonably agree with the numerical results despite the complicated parametric dependence of the HHFHS. Crucial parametric dependence of the HHFHS has been also explored using the correlation.