Newsletter  2012.4  Index

Theme : "Hydrogen Flow"   Preface (M. Ogino, H. Hamakawa, K. Morimoto) Integrated Computational Study of Atomization Process of Liquid Hydrogen Pin-Hall Leakage Jet Jun ISHIMOTO (Tohoku University) Experimental study on hydrogen dispersion Masahiro INOUE (Kyushu University) Fundamental Characteristics for Open-Jet Flame of High-Pressurized Hydrogen Keiji TAKENO (Mitsubishi Heavy Industries, Ltd., Nagasaki R&D Center) Numerical Simulation of Leaking Hydrogen Dispersion Kazuo Matsuura (Ehime University)   |  Back  |

 

Integrated Computational Study of Atomization Process of Liquid Hydrogen Pin-Hall Leakage Jet

Jun ISHIMOTO Institute of Fluid Science, Tohoku University

Abstract

The fundamental structure of the liquid atomization behavior of an liquid hydrogen jet flow through a pinhole nozzle is numerically investigated and visualized by a new type of integrated simulation technique. The integrated CFD analysis focuses on the heat transfer effect on the consecutive breakup of a cryogenic liquid column, the formation of a liquid film, and the generation of droplets in the outlet section of the pinhole nozzle.

According to the present computation, the cryogenic atomization rate and the liquid hydrogen droplets-gas two-phase flow characteristics are found to be controlled by the turbulence perturbation upstream of the pinhole nozzle, hydrodynamic instabilities at the gas-liquid interface and shear stress between the liquid core and the periphery of the liquid hydrogen jet. Furthermore, calculation of the effect of cryogenic atomization on the jet thermal field shows that such atomization extensively enhances the thermal diffusion surrounding the liquid hydrogen jet flow.

Key words

liquid hydrogen jet, atomization, tank leakage, multiphase flow, cryogenics

Fig.  Instantaneous iso-surface of liquid-phase volume fraction (F=0.5)
with velocity scalar magnitude.