An inexpensive, lightweight, and relatively quiet engine reactor that has the potential to achieve thermal efficiency over 50% for small engines was proposed in our previous reports, which is achieved with colliding supermulti-jets that create air insulation to encase burned gas around the chamber center, avoiding contact with the chamber walls and piston surfaces. The colliding of pulse jets can maintain high pressure ratio for various air-fuel ratios, whereas traditional homogeneous compression engines due to piston cannot get high pressure ratio at stoichiometric condition. Emphasis is also placed on the fact that higher compression in this engine results in less combustion noise because of encasing effect. Here, a small prototype engine having supermulti-jets colliding with pulse and strongly-asymmetric double-piston system is examined by using computational experiments. Pulse can be generated by the double piston system of a short stroke of about 40mm. Computations at some loads and engine speeds show a potential of high thermal efficiency over 60%, because there is very less heat loss on combustion chamber and piston surface. Design guidelines on the number of jets colliding and the size ratio of bore size and jet diameter are also shown in this report.
|ジャーナル||SAE Technical Papers|
|出版ステータス||Published - 2014 11月 11|
|イベント||SAE/JSAE 2014 20th Annual Small Engine Technology Conference and Exhibition, SETC 2014 - Pisa, Italy|
継続期間: 2014 11月 18 → 2014 11月 20
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