燃焼シミュレーションコードKIVAによるディーゼルエンジン燃焼系（ピストン形状，インジェクタ仕様、噴射パターン、スワール）の最適化手法を開発した。GAやSAなどの最適化アルゴリズムと直接リンクさせるのではなく，応答曲面を都度更新する手法を採用することにより，短期間で最適化完了できることが分かった。

抄録全体を表示

A phenomenological soot model coupled with detailed chemistry was introduced into the 3-D CFD code KIVA-3V. The model treats soot formation as four global stages including particle nucleation, surface growth, surface oxidation, and particle coagulation. In paper Particulate Matter Formation process of a Diesel engine under various O_2 concentration conditions were analyzed. As a result, predicted in-cylinder pressure and RHR histories have good agreement with measured ones. It can be predicted qualitative trends of measurement data of soot emission under wide range of O_2 concentration conditions.

抄録全体を表示

This paper describes with 3-dimentional Computational Fluid Dynamics study to predict ignition and combustion process of a passenger diesel engine under various O_2 concentration conditions. The 3-D CFD code used is KIVA-3V modified on a droplets collision model and velocity interpolation with PaSR turbulence-chemistry interaction model. Diesel oil surrogate mechanism in which oxidation of hydrocarbons, soot and NO_x formations were described was also used for Chemical reaction. As a result, predicted in-cylinder pressure and RHR histories have good agreement with measured ones. It can be predicted qualitative trends of measurement data of NO_x under wide range of O_2 concentration conditions.

抄録全体を表示

高圧・早期燃料噴射とEGRを組み合わせた予混合圧縮着火燃焼が直接噴射ディーゼル機関の低公害化には有効である．本研究では汎用数値流体コードKIVA-3Vをベースに燃料噴射ノズル内キャビテーションの崩壊エネルギを考慮した噴霧モデルを用いて上記燃焼について数値解析を実施したのでこれを報告する．

抄録全体を表示