Smart microchannel heat exchangers with Built-In graded SMA vortex generators that responds to random hotspots

Abstract

Heat sinks with built-in shape memory alloy vortex generators (SMA-VGs) can respond intelligently to temperature variations in a channel without the need for external control. However, ordinary vortex generators fail to respond effectively to random hot spots because the coolant temperature in the channel accumulates along the path. Therefore, this study proposes a smart heat sink with graded SMA-VGs to intelligently recognize the locations of hotspots. The influence of the overheating area was reduced, and the temperature uniformity of the device was improved using the temperature field change of the heat sink to drive the deformation of the vortex generator. In this paper, the principle of smart microchannel heat sinks that can respond to random hotspots is analyzed, and the effects of adaptive pitch adjustment on the temperature and flow of the channel with local hotspots are investigated. Subsequently, graded SMA-VGs are designed and manufactured, and the cooling performance of the smart heat sink is experimentally investigated. The experimental results show that, when compared with traditional coil vortex generators, a channel with built-in graded SMA-VGs performs better in heat transfer while using lower pumping power, resolving the problem of random hotspots in high heat flux devices and demonstrating broad application prospects.