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The Szorenyi Three-Chamber Rotary Engine Concept
ISSN: 0148-7191, e-ISSN: 2688-3627
Published September 09, 2019 by SAE International in United States
Annotation ability available
Currently automotive engines are reciprocating or Wankel rotary engine types. Reciprocating engines are bulky, heavy and complex, mainly due to the intake and exhaust valves and their associated cam-train. Wankel engines have a low rotor rev limit, and have inefficient sealing of the apex seals leading to poor economy and undesirable emission gases. The Rotary Engine Development Agency (REDA) has designed a new three-chamber rotary internal combustion engine concept using an adaptation of the patented Szorenyi Curve. The new design is an evolution of the design which was the subject of SAE Technical Paper 2017-01-2413 and SAE publication ‘So You Want to Design Engines: UAV Propulsion Systems’. This paper describes the features of the new three-chamber engine concept and includes an analysis of the major shortcomings of the Wankel engine. The Wankel engine’s geometry results in excessive crankshaft deflection at high engine revs due to the centrifugal force of the rotor which is eccentric to the crankshaft. This results in a low rotational speed limit. Analysis of the Wankel design reveals that the rotational speed limit cannot be increased by increasing the diameter of the crankshaft. Also, analysis of the apex seal reveals that the shape of the stator accelerates the seal inwards during the intake and power stroke and, at the same time, the seal experiences a large change in its contact angle with the stator surface. These effects combine to produce poor conditions for sealing the combustion chamber of the Wankel engine. The paper identifies that the Szorenyi three-chamber engine design does not have these same issues because its symmetrical rotor enables a high rotational speed, and its continuously concave stator profile ensures an outward acceleration of the apex seal and much less change of contact angle with the stator surface. The paper concludes that the Szorenyi engine has the potential to replace Wankel and reciprocating engines in a range of applications and is particularly suited to light aircraft.
CitationKing, P., "The Szorenyi Three-Chamber Rotary Engine Concept," SAE Technical Paper 2019-24-0168, 2019, https://doi.org/10.4271/2019-24-0168.
- United States Patent , “Hinged Rotor Internal Combustion Engine,” Patent No. US 6,718,938 B2, Date of Patent Apr. 13, 2004.
- King, P. , “The Development of the Four-Chamber Szorenyi Rotary Engine,” SAE Technical Paper 2017-01-2413 , 10 August 2017, doi:10.4271/2017-01-2413.
- Kucinski, W. , So You Want to Design Engines: UAV Propulsion Systems (SAE International, 2019). ISBN:978-0-7680-9175-5.
- IP Australia Provisional Patent Application number 2019902405 , The internal profile of a stator for a rotary engine using the K-curve, based on the Szorenyi Curve, to allow for a crankpin to be located in the centre of each of the rotor segments of a three chamber rotary engine, dated 6 July 2019.
- Knoll J., Vilmann C.R., Schock H.J., and Stumpf R.P. , “A Dynamic Analysis of Rotary Combustion Engine Seals,” National Aeronautics and Space Administration, Lewis Research Centre, Cleveland, Ohio, NASA-TM-83536, 1984.
- Yamamoto, K. , Rotary Engine (Toyo Kogyo Company Ltd, 1971).
- Kweon Chol-Bum M. , “A Review of Heavy-Fuelled Rotary Engine Combustion Technologies,” Army Technology Directorate, Army Research Laboratory, Aberdeen Proving Ground, MD, ARL-TR-5546, 2011.