A comparative evaluation of thermodynamic performance of a single-cylinder linear engine and conventional engine

Abstract

Linear engine has been presented as a potential substitute for conventional crank engine (CCE). This paper proposes a multi-dimensional thermodynamic model which couples piston motion, scavenging and combustion to reveal the thermodynamic performance of a single-cylinder linear engine (SCLE) by comparing a CCE. The results indicate that the SCLE provides longer gas exchange duration for exhaust cleaning, and it has a shorter residence time near top dead center for combustion. As a result, the SCLE shows higher scavenging efficiency and more complete exhaust, although the longer gas exchange duration of the SCLE also has a negative impact on the trapping efficiency. Moreover, it also finds that the SCLE operates with a lower combustion efficiency and longer combustion duration than the CCE due to its faster motion around top dead center. Therefore, the thermal efficiency of SCLE is lower.

Keywords

• Single-cylinder linear engine
• Conventional crank engine
• Gas exchange
• Combustion