薄液膜の撥水型ドライアウト防止によるミニチャネル内流動沸騰熱伝達促進

抄録

In boiling in a small channel, thin liquid film is formed around the elongated bubble, and the heat transfer performance strongly depend on its formation and evaporation characteristics. On a bare silicon surface, the thin liquid film ruptures and then dewets. This dewetting type dry-out causes heat transfer deterioration and so has to be prevented to keep a high heat transfer performance of thin liquid film evaporation. In this study, superhydrophilic surfaces were fabricated by adding SU-8 micro-pillar array on the wall. The superhydrophilic structures successfully prevented the dewetting-type dry-out in the boiling experiments, and shows larger heat transfer coefficient and critical heat flux than a bare silicon surface. Liquid propagation through spacing between the pillars prevented the dewetting-type dry-out and delays dry-out due to evaporation. The critical heat flux was enhanced by a factor of around two by using pillar structures, and optimization of structure dimensions will realize higher boiling heat transfer performance in the future.