Design and simulation of a rapid compression and expansion machine based on a single cylinder engine

WANG Xin-ran1, LI Tie1,2, HUANG Shuai1
(1.State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University, Shanghai 200240, China;
2.Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration, Shanghai 200240, China)

Abstract: In order to analyze the internal flow field, visible ignition and combustion process in the internal combustion engine, a study of the design of a rapid compression and expansion machine was executed by the combination design method of a single-cylinder engine and a visible constant volume chamber. Firstly, a piston was installed on the equipment to create dynamic flow filed in the combustion chamber, a visible constant volume chamber was used to observe the dynamic flow field and the ignition and combustion process inside the combustion chamber, the NI CompactRIO 9036 hardware system, was used to program to control the rapid compression and expansion machine system. Secondly, the ambient pressure at the ignition moment was changed by adjusting the initial charge pressure, and the flow velocity was changed by adjusting the engine speed. The flow field of combustion chamber in different operating conditions was simulated. Visible studies on ignition and combustion processes were carried on. Finally, the dynamic flow field simulation and ignition experiments were carried out; the dynamic flow field, the ignition and combustion process inside the rapid compression and expansion machine were studied by means of the flow field simulation and the ignition experiments. The results of flow field simulation research indicate that flow velocity near the spark plug during ignition can be varied from 5.20 m/s to 46.25 m/s by adjusting engine speed and ignition timing, but environmental pressure has little influence on it. The results of ignition experiments research of various operating conditions are consistent with the simulation results, indicating that the machine can provide important support for visualization study of the ignition and combustion process of lean mixture with strong turbulence condition.
Key words: visible research; rapid compression and expansion machine; flow field simulation; ignition experiments