The flow and heat transfer characteristics of supercooled water based on the nano-superhydrophobic surface

摘要

Dynamic ice making by supercooled water is one of the most promising ways to produce ice slurry at present. However, its main defect is that the supercooler is easy to have ice blockage. A nano-fluorocarbon thin film of about 10nm thickness coated on the solid surface, which is composed of a large number of uniformly distributed tiny bumps and holes, making the coated surface present super-hydrophobicity and the contact angle reach 163.01 degrees with a small contact angle hysteresis. Based on the properties of nano-superhydrophobic surface, the characteristics of flow and heat transfer of supercooled water are analyzed in the flow regime with low reaction coefficient. It was found that: due to the existence of velocity slip on the nano-superhydrophobic surface, the flow and average flow rate of supercooled water increase, reducing the mechanical energy dissipation in the process of supercooled water flow, and the flow resistance is smaller with a good heat transfer performance. However, whether the effect of the super-hydrophobic surface can enhance or deteriorate the transport mechanisms depending to the flow regime and surface structure.