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Journal of Combustion
Volume 2017, Article ID 1742138, 8 pages
Research Article

Small Engines as Bottoming Cycle Steam Expanders for Internal Combustion Engines

Department of Engineering, Design and Mathematics, University of the West of England, Coldharbour Lane, Bristol BS16 1QY, UK

Correspondence should be addressed to Rohitha Weerasinghe; moc.oohay@ahtihorhtijus

Received 16 January 2017; Revised 4 April 2017; Accepted 20 April 2017; Published 31 May 2017

Academic Editor: Paul Hellier

Copyright © 2017 Rohitha Weerasinghe and Sandra Hounsham. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Heat recovery bottoming cycles for internal combustion engines have opened new avenues for research into small steam expanders (Stobart and Weerasinghe, 2006). Dependable data for small steam expanders will allow us to predict their suitability as bottoming cycle engines and the fuel economy achieved by using them as bottoming cycles. Present paper is based on results of experiments carried out on small scale Wankel and two-stroke reciprocating engines as air expanders and as steam expanders. A test facility developed at Sussex used for measurements is comprised of a torque, power and speed measurements, electronic actuation of valves, synchronized data acquisition of pressure, and temperatures of steam and inside of the engines for steam and internal combustion cycles. Results are presented for four engine modes, namely, reciprocating engine in uniflow steam expansion mode and air expansion mode and rotary Wankel engine in steam expansion mode and air expansion mode. The air tests will provide base data for friction and motoring effects whereas steam tests will tell how effective the engines will be in this mode. Results for power, torque, and diagrams are compared to determine the change in performance from air expansion mode to steam expansion mode.