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Effects of Port Angle on Scavenging of an Opposed Piston Two-Stroke Engine

Conference · · SAE Technical Paper Series
DOI:https://doi.org/10.4271/2022-01-0590· OSTI ID:1906655

Opposed-piston 2-stroke (OP-2S) engines have the potential to achieve higher thermal efficiency than a typical diesel engine. However, the uniflow scavenging process is difficult to control over a wide range of speeds and loads. Scavenging performance is highly sensitive to pressure dynamics, port timings, and port design. This study proposes an analysis of the effects of port vane angle on the scavenging performance of an opposed-piston 2-stroke engine via simulation. A CFD model of a three-cylinder opposed-piston 2-stroke was developed and validated against experimental data collected by Achates Power Inc. One of the three cylinders was then isolated in a new model and simulated using cycle-averaged and cylinder-averaged initial/ boundary conditions. This isolated cylinder model was used to efficiently sweep port angles from 12 degrees to 29 degrees at different pressure ratios. Results indicate that scavenging performance is correlated with the bulk swirl ratio generated by these port angles. Scavenging performance is also sensitive to the pressure ratio across the engine. It was concluded that, for a given pressure ratio, the smallest port angle produces the best scavenging; however, previous work indicates lower bulk swirl ratio during combustion can have an impact on emissions formation.

Research Organization:
Achates Power, Inc.
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Transportation Office. Vehicle Technologies Office
DOE Contract Number:
EE0009202
OSTI ID:
1906655
Report Number(s):
DOE-API-9202-1
Journal Information:
SAE Technical Paper Series, Journal Name: SAE Technical Paper Series Vol. 2022; ISSN 0148-7191
Publisher:
SAE International
Country of Publication:
United States
Language:
English

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