LAUSR

Abstract Characteristics based on hydrogels deformation are adopted to control the coolant flow distribution of the micro-channel, the adaptive heat dissipation performance of the fractal micro-channel heat sink embedded with hydrogels (GFCY) was numerically investigated. Under the uniform heat flux, the temperature decrement of the GFCY heat sink is twice more than the micro-channel heat sink embedded with three groups of micro pin fins between second stage channels (FCY-2), which are embedded with no hydrogels. Meanwhile, the ultimate cooling capacity of the GFCY heat sink increased by 30 % on average compared with the FCY-2 heat sink, showing better temperature uniformity and ultimate cooling capacity. However, at a single hot spot, the GFCY heat sink has a smaller temperature gradient of the entire heat surface, which improves temperature uniformity and enhances the heat dissipation capacity. Putting hot spots into different locations, it is found that the hydrogels deformation is beneficial to enhance the cooling capacity. The hydrogels near hot spot undergo deformation, causing an increase of coolant flow to enhance the cooling capacity of the channel, meanwhile increasing the uniformity of the temperature distribution. Furthermore, changed the area of the hot spot, an increase in hot spot area significantly enhances the sensitivity to heat flux, which results in more hydrogels deformation and stronger adaptive cooling capabilities. Therefore, it's revealed that compared with the heat sink without embedded hydrogels, the GFCY heat sink can achieve the best cooling performance.