Theoretical and experimental research on the port timing of a compressed air engine

ABSTRACT

This study presents a theoretical model and an experimental investigation of a piston engine driven by compressed air. The compressed air engine (CAE) is proposed which is modified from a conventional internal combustion engine. The experiments in this study have used a test bench to examine the output torque and power performance and pressure variations of CAE at different port timing. The study has found that port timing has a direct influence on the working performances of CAE. Based on the theoretical analysis, the model of CAE developed for engine performance analysis and working process is described in this paper. In addition, good agreement of simulation results is obtained between the model and the test. The results show that, as intake advance angle increases, the cylinder pressure decreases during the expansion stroke stage and the exhaust stroke stage. An increase of cylinder pressure is shown at larger intake sustain angle. Moreover, one can find that compared with exhaust advance angle, the intake advance angle and the intake sustain angle have more influence on output torque and power. Consequently, this study of this paper will provide a theoretical and an experimental basis for further study on optimizing the design of CAE.

KEYWORDS:

• Compressed air engine
• port timing
• theoretical model
• experimental investigation
• cylinder pressure

Acknowledgments

The authors would like to thank the automobile company SGMW in China for its kind assistance with the four-stroke IC engine fused for the present study.

Disclosure statement

The authors declare that there is no conflict of interests regarding the publication of this paper.

Additional information

Notes on contributors

Fancong Zeng

Fancong Zeng is a teacher of vehicle engineering at Jianghan University, Hubei, China. He received his phD in Mechanical engineering from Wuhan University of Technology, China, in 2019. His areas of current interest are air engine, pneumatic transmission dynamics, etc.

Jinli Xu

Jinli Xu is a professor of mechanical engineering at Wuhan University of Technology, Hubei, China. He received his phD  in mechatronic engineering from Wuhan University of Technology, China, in 2011. His areas of current interest are shock and vibration of automobile chassis, study in air engine , etc.