著者

高橋 易資 野村 友和 石間 経章 小保方 富夫

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:03875016)

巻号頁・発行日

vol.71, no.706, pp.1694-1701, 2005-06-25 (Released:2011-03-03)

参考文献数

17

被引用文献数

2 4

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A computational fluid dynamics (CFD) code with partial cells in Cartesian coordinate (PCC) method has been developed. The merit of this method is that input data preparation time is extremely short because computational mesh data are separated from geometry data. However, a general Cartesian coordinate method has a big subject in calculation accuracy. One of the factors is precision in geometry expression around the complicated shape, and another is a turbulence model near the wall because mesh is independent from the boundary and not fitted with it. Therefore, discretization equations were derived based on Finite Volumetric Method, and a combination of the wall function and a low Reynolds number k-ε turbulence model was proposed here. This paper describes implementation of this method and shows the results compared with experimental data by particle image velocimetry (PIV) at the steady flow in the cylinder of a 4-valves S.I. engine. The comparison results of velocity vector maps show good agreement between CFD and PIV.

著者

カマル イザム 上田 隆正 荒木 幹也 志賀 聖一 宮下 直幸 小保方 富夫 津江 光洋 河野 通方

出版者

一般社団法人日本エネルギー学会

雑誌

日本エネルギー学会大会講演要旨集

巻号頁・発行日

no.12, pp.310-311, 2003-07-30

著者

加藤 真亮 川島 久宜 石間 経章 金井 昌二 関 孝史 関 孝史 鈴木 秀和 小保方 富夫

出版者

公益社団法人 自動車技術会

雑誌

自動車技術会論文集 (ISSN:02878321)

巻号頁・発行日

vol.43, no.4, pp.887-892, 2012

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ピストンフリクション低減のために,ピストンとシリンダ間における油膜挙動の解析が必要である.透明シリンダを持つ可視化エンジンに対しLIF/PIV法を用いて油膜の厚さと速度の同時計測を行った.実験からオイルリング直下のバレル形状がピストンスカート上の油膜に与える影響を明らかにした.

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.