2010 年 27 巻 3 号 p. 233-242
In the present study, we employed the recent micron-order machining technology on the cooling surface and produced the artificial micro-ordered groove pattern. The frost and defrost phenomena on the artificial surface with micro-structure are experimentally investigated. The effects of the groove depth or pattern pitch between grooves on the frost phenomenon were focused. The direct observations of the frost and defrost phenomena on the surface were carried out by using the digital microscope with high spatial resolution. It is cleared that the grooves on the surface strongly affect the frost and defrost phenomena, especially the generation of the super-cooled droplets on the surface, which can be observed at the beginning of cooling. The water drainage after frost melting was also strongly affected by the micro grooves.