Study of droplet breakup process in transonic spray by micro laser probe

2015 Fiscal Year Final Research Report

• Project/Area Number: 25420127
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Fluid engineering
• Research Institution: Nagasaki University
• Principal Investigator: UEKI Hironobu 長崎大学, 工学研究科, 教授 (30160154)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 液体微粒化 / レーザー2焦点流速計 / 燃料噴霧 / 噴孔近傍 / 液滴サイズ / ウエーバー数 / マッハ数

Outline of Final Research Achievements

Measurements of temporal and spatial changes in the velocity and size of droplets of transonic diesel fuel sprays were conducted near the nozzle orifice by a laser 2-focus velocimeter (L2F). The injection pressure was set at 40 and 135MPa. Measurement positions were located at 10 mm from the nozzle exit. The distance between droplets in the direction of droplets’ flight was determined by multiplying the droplet velocity and the time interval between 2 droplets sequentially passing the measurement volume. The result showed that the droplet size near the spray center was larger than that at the periphery of fuel sprays. When the injection Mach number became higher, the size of droplets became larger. The number density at the center of fuel sprays was lower than that at the periphery of fuel sprays.

Free Research Field

熱流体工学