Thermal performance analysis of a hybrid micro-channel, -pillar and -jet impingement heat sink

The present study proposes a novel hybrid design of a heat sink based on micro-channel, -pillar and -jet impingement. A three-dimensional numerical model is constructed to investigate the thermal performance of the proposed design for steady state, incompressible and laminar flow. A constant heat flux was applied on one side of the substrate while on the other side micro-channels, -pillars and -jet impingements were arranged. The performance of the newly designed hybrid heat sink was compared with the basic designs of parallel flow micro-channels, micro-channels with micro-pillars, and micro-jet impingement heat sinks. The parametric analysis of the hybrid heat sink was performed by forming two dimensionless variables, i.e., ratios of standoff (distance of nozzle exit to impingement surface) to jet diameter and jet pitch to jet diameter. The performance of the hybrid heat sink was investigated in terms of heat transfer coefficient, Nusselt number, pressure-drop, overall thermal resistance and pumping power. The hybrid designs with low jet pitch to jet diameter ratios offered high heat transfer coefficient while high jet pitch to jet diameter ratios offered low pressure-drops. High heat transfer coefficients were observed for jet and pillar combinations and low thermal resistance and pumping power were observed for standoff to jet diameter ratio close to 2 and 3.