Cooling high heat flux with flow boiling in 2D-structured radial microchannel heat sink

Abstract This work proposes a novel two-dimensional-structured radial microchannel heat sink (RMHS) to effectively dissipate high heat flux, which owns easily manufactured characteristics. The RMHS is formed by orderly arranged pin fins involving two branching microchannel structures. The fluid flows into the RMHS through the central inlet and then experiences the continuous split and mixing imposed by the branching structures. The generated vapor bubble experiences a frequent breakup and coalescence process with the boiling phenomenon, among which the thin liquid film thickness can be triggered. The RMHS is fabricated using the silicon etching technique. A series of visualization experiments are conducted to test the performance of RMHS and reveal the related physical mechanisms. The evolution of bubble dynamics within the RMHS is recorded with a high-speed photographic system. The features mentioned above of RMHS confer excellent boiling heat transfer performance. At 600 ml min −1 volumetric flow rate, the maximum dissipated heat flux reaches 1035 W cm −2 with an area of 1 cm 2 . The present study is hoped to provide valuable insights into designing a two-phase microchannel heat sink for the thermal management of electronic devices.