著者

増田 糧 河村 清美 永岡 真 増渕 匡彦 小森 啓介

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集B編 (ISSN:18848346)

巻号頁・発行日

vol.78, no.793, pp.1584-1597, 2012 (Released:2012-09-25)

参考文献数

25

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A liquid fuel injection nozzle with a novel fuel atomization strategy which actively utilizes the effect of collapse of cavitation bubbles in a liquid jet is proposed. The nozzle comprises two orifices and an intermediate cavity between the orifices. The role of the upstream first orifice is to generate the cavitation bubbles at both inlet and exit of the orifice. The intermediate cavity is placed to hold the cavitation bubble within it. The role of the downstream second orifice is to mix the cavitation bubbles and liquid fuel, and to inject the mixture into atmosphere. Each size and relative positions of the first orifice, the intermediate cavity and the second orifice were studied using multi-phase computational fluid dynamics. Finally, a poppet type nozzle whose void fraction at the nozzle exit is 0.5 was designed.

著者

荒木 幹也 嶋津 有宏 小保方 富夫 石間 経章 志賀 聖一 増渕 匡彦 杉本 知士郎

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. B編 (ISSN:03875016)

巻号頁・発行日

vol.73, no.726, pp.622-630, 2007-02-25

被引用文献数

9

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Atomization characteristics of an ultrasonic fuel injector using a micro nozzle array were investigated experimentally. Micro nozzles whose exit diameter is d=3, 6 and 9μm are mounted on a thin metal film. The number of the micro nozzle is 2.0×10^4. Using an ultrasonic oscillator, gasoline is periodically pushed out from the micro nozzles at the frequency of 63.6 kHz. A disk-type PZT is used as an ultrasonic oscillator, and the oscillation is amplified using a step-type horn. The input voltage is varied from 0 to 200 V. At the natural frequency, the oscillation amplitude of the horn is about 10μm. The droplet diameter and velocity are measured with a phase Doppler analyzer at 15 mm downstream from the micro nozzle array. For d =3μm, the Sauter mean diameter (SMD) is about 10μm, and the fuel flow rate is 0.023 cc/s. The SMD is much smaller when compared to conventional port fuel injectors. For d=6μm, the SMD is about 10 to 18μm, and the fuel flow rate is 0.055 cc/s. For d=9μm, the SMD is about 16 to 28μm, and the fuel flow rate is 0.41 cc/s. It is shown that, using the micro nozzle array, a uniform-diameter steady spray can be obtained without high-pressure fuel pump and nozzle type injectors.