A Comprehensive Numerical Analysis of the Scavenging Process in a Uniflow Two-Stroke Diesel Engine for General Aviation

Energies

Paolo Caso¹  Alessandro Coclite²  Vinicio Magi³  Maria Faruoli³  Annarita Viggiano³ 

[1] Costruzioni Motori Diesel CMD S.p.A., San Nicola La Strada, 81020 Caserta, Italy;Dipartimento di Ingegneria Elettrica e dell’Informazione, Politecnico di Bari, Via Re David, 70125 Bari, Italy;Scuola di Ingegneria, Università degli Studi della Basilicata, Viale dell’Ateneo Lucano, 85100 Potenza, Italy;

关键词: two-stroke engines;    scavenging performance;    computational fluid dynamics;    engine design;   

DOI  :  10.3390/en14217361

来源: DOAJ

【 摘 要 】

The scavenging process of two-stroke engines plays a fundamental role in cylinder flow patterns and in the overall engine performance. In this work, 3D CFD simulations of the scavenging in a uniflow, two-stroke, compression ignition engine for general aviation, named GF56, have been performed by using a 3D finite-volume FANS equations solver with k-$ϵ$ closure. The GF56 engine consists of six cylinders, separated into two quasi-symmetric banks. Both the right and the left banks, together with the corresponding cylinders, are carefully analyzed. Charging and trapping efficiencies are computed as a function of the delivery ratio for different mass flow rates entering into the plenum, and the influence of the exhaust pressure and of the cylinder’s location in the bank are analyzed. The results show that the fresh air trapped during the scavenging process is quite similar for each cylinder of the right bank and it is about 92% of the in-cylinder mass. The cylinder’s location in the bank by itself slightly affects the scavenging performance, whereas the pressure profile at the outlet section has a major role. The design of the intake ports is fundamental for establishing the in-cylinder flow field and a new ports configuration is proposed to enhance the swirl ratio and, consequently, the scavenging performance with high delivery ratios.

【 授权许可】

Unknown