• Journal of ILASS-Korea
• /
• v.25 no.1
• /
• pp.15-20
• /
• 2020

This study aims to investigate injection rate and microscopic spray characteristics of diesel fuel containing fine air bubble (FBD). fine bubble was generated by cavitation theory using bubble generator. Fuel spray was injected into constant volume chamber and visualized by high speed camera. The injection rate data was acquired with bosch tube method. Injection rate of finebubble diesel was very similar with that of diesel. It showed slightly faster injection start by 5 ㎲ attributed to the low viscosity characteristics. In microscopic spray visualization, fine bubble diesel spray showed unsymmetric spray shape compared with diesel spray. It also showed very vigorous spray atomization performance during initial spray development. Improved atomization was also attributed to the low viscosity and surface tension of finebubble diesel fuel.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2012.05a
• /
• pp.180-186
• /
• 2012

A water-flow test for acceptance verification is carried out for a nonimpinging-type injector prior to the design-performance verification of 70 N-class liquid-rocket engine under development. It is observed that there exist varying characteristics of atomization among the injector-orifices caused by a fabrication crudeness of orifice holes which can be judged from a microscopic standpoint. The flow shedding phenomenon and ruffle on the surface of liquid column (or droplet) could be caught from the instantaneous spray images.