Effects of intake and exhaust valve timing on the performance of an air‐powered rotary engine

Abstract

This work is aimed at improving the performance of the air‐powered rotary engine. A dynamic simulation model which includes an eccentric motion and rotary valve movement was established by our particle image velocimetry (PIV) experimental data. Then the power and specific steam consumption (SSC) was evaluated. The pressure distribution in the chamber was obtained which was difficult to obtain through experiment. Simulation results showed that for the work process and pressure distribution, the intake valve timing mainly affected the intake expansion stage (A2) and pure expansion stage (B). Due to this, a relatively low pressure was distributed in the middle of the chamber and this was beneficial to the intake and work processes. The exhaust valve timing mainly affected the exhaust stage (C) and initial intake stage (A1). Therefore, a relatively high pressure which was distributed in the middle‐rear of the chamber was beneficial to the exhaust processes. For the power and SSC, the power increased initially then decreased and the SSC decreased with the increase of intake advance angle respectively. Both the power and the SSC increased with the increase of intake duration angle. The power increased while the SSC decreased with the increase of exhaust advance angle. The power increased and the SSC decreased initially then increased with the increase of exhaust duration angle. The preferred parameters were found to be 30° CA, 240° CA, 30° CA, and 280° CA. These improved parameters had a 2.7% increase in the power and also a 2.4% decrease in the SSC. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 1462–1474, 2018