書誌事項
- タイトル別名
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- Numerical analysis of needle eccentricity effects on internal flow of enlarged VCO diesel injector
抄録
The VCO (Valve Covered Orifice) nozzle is known to reduce unburned hydrocarbon emission from direct-injection diesel engine. However, high-pressure fuel injection causes needle eccentricity which results in non-uniformity of sprays and deterioration of emission characteristics. Present study numerically investigates the needle eccentricity effects on the internal flow of the large-scaled VCO nozzle by using STAR-CCM+ (ver. 8.02.011), and obtained results are compared with those of a corresponding experiment. Swirling flow is formed in the nozzle hole due to the needle eccentricity. As increasing the swirl strength, air entrainment from the nozzle hole outlet is generated, and spray cone angle is decreased. However, in the range of large needle eccentricity, growth of the swirling flow decays, and the spray cone angle is saturated at certain value. These tendencies are also observed in the experiment. Thus, it is confirmed that the present numerical simulation reproduce the actual phenomena qualitatively. Furthermore, effects of edge curvature of the nozzle hole inlet is also numerically investigated as a key factor acting on the internal flow characteristics. As the edge curvature increases, the swirling flow in the nozzle hole considerably grows, and the air entrainment into the nozzle hole is greatly enlarged. Also, spray characteristics is extremely changed.
収録刊行物
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- 日本機械学会論文集
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日本機械学会論文集 80 (812), TEP0094-TEP0094, 2014
一般社団法人 日本機械学会
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詳細情報 詳細情報について
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- CRID
- 1390282680491983616
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- NII論文ID
- 130003399179
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- ISSN
- 21879761
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- 本文言語コード
- ja
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- データソース種別
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- JaLC
- Crossref
- CiNii Articles
- KAKEN
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- 抄録ライセンスフラグ
- 使用不可