2011 Fiscal Year Final Research Report

Ice nucleation of water droplet in supersonic air streams

Research Project

Project/Area Number	21760145
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Single-year Grants
Research Field	Fluid engineering
Research Institution	Fukuoka Industrial Technology Center
Principal Investigator	SHUZENJI Kiyotaka 福岡県工業技術センター, 機械電子研究所, 研究員 (00416504)
Project Period (FY)	2009 – 2011
Keywords	混相流 / 氷核生成
Research Abstract	The process of the atomization of water and the ice nucleation of the droplet in Laval nozzle were investigated through the experiment with a phase Doppler particle analyzer and the unsteady thermal conductive analysis by the Heisler chart. The experimental results show that the droplet was atomized and accelerated primarily in the region of 60mm downstream from the throat. The profile of the axial velocity at the nozzle exit is similar to the shape of Hagen-Poiseuille flow which fully developed. The axial mean velocity and the arithmetic mean diameter were 473m/s and 5.6um respectively at the nozzle exit with the water flow rate of 10 mL/min. The thermal conductive analyses indicate that the droplet which diameter is smaller than 5 um freezes inside the nozzle regardless the relative velocity for the air streams.