{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T01:00:16Z","timestamp":1759971616864,"version":"build-2065373602"},"publisher-location":"400 Commonwealth Drive, Warrendale, PA, United States","reference-count":13,"publisher":"SAE International","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"abstract":"<div class=\"section abstract\"><div class=\"htmlview paragraph\">One way to increase efficiency and performance of 2-stroke engines is the addition of an exhaust valve to control the opening\/closure of the exhaust port. With this implementation it is possible to change the exhaust timing for different conditions. However, conventional systems cannot change the exhaust opening and closure timings independently. The work herein presented shows the development of a new exhaust rotary valve enabling the control of the opening independently from the control of the closure of the exhaust port. The study is based on kinetic and thermodynamic analysis.<\/div><div class=\"htmlview paragraph\">Some manufacturers use exhaust rotary valves but none of them performs a fully rotary motion. This kind of motion has various benefits such as smoothness and most notably the ability to control both the opening and the closure timing of the exhaust independently.<\/div><div class=\"htmlview paragraph\">Regarding the kinematic analysis, a simple model was created to determine the most suitable valve angles. This combines the kinematic of the piston with the kinematic of the valve in order to determine the required valve angles to perform the required exhaust timing. With this model the authors were able to obtain the valve parameters for different engine conditions and visualize geometry limitations of the valve for each engine event.<\/div><div class=\"htmlview paragraph\">For the thermodynamic analysis the authors were able to use the data from the referred kinematic model to create a 3D model of the engine. The 3D model was then implemented using the software CONVERGE CFD which simulated the flow and thermal effect of the valve on the engine behaviour. The simulations were performed for a single engine geometry but with different valve conditions\/geometry and different compression ratios. It was concluded that indeed it is possible to effectively implement this kind of valve and achieve the intended over-expansion effect.<\/div><\/div><\/jats:p>","DOI":"10.4271\/2016-01-1054","type":"proceedings-article","created":{"date-parts":[[2016,4,5]],"date-time":"2016-04-05T01:30:20Z","timestamp":1459819820000},"source":"Crossref","is-referenced-by-count":3,"title":["A New Rotary Valve for 2-Stroke Engines Enabling Over-Expansion"],"prefix":"10.4271","volume":"1","author":[{"given":"Jorge","family":"Martins","sequence":"first","affiliation":[{"name":"Universidade do Minho"}]},{"given":"Carlos","family":"Pereira","sequence":"additional","affiliation":[{"name":"Universidade do Minho"}]},{"given":"F.P.","family":"Brito","sequence":"additional","affiliation":[{"name":"Universidade do Minho"}]}],"member":"2796","published-online":{"date-parts":[[2016,4,5]]},"reference":[{"key":"ref0","unstructured":"Martins , Jorge 2013 Internal Combustion Engines 4 th Porto Publind\u00fastria"},{"key":"ref1","unstructured":"Yamaha 2009 Yamaha technology 1980: YPVS (Yamaha Power Valve System) http:\/\/www.yamaha-motor.eu\/designcafe\/en\/about-design\/technology\/index.aspx?segment=About%20-Design%20-%20Technology&view=article&id=440980 2 March 2015"},{"key":"ref2","unstructured":"Anderson , S. 1986 Exhaust Power Valves Cycle World Magazine April 89 94"},{"key":"ref3","unstructured":"Zim. Korn 2002 Schematics http:\/\/www.nsr125.com\/schem.htm 1 May 2015"},{"key":"ref4","unstructured":"Dan 1999 Power valves http:\/\/www.dansmc.com\/powervalve.htm 6 April 2015"},{"key":"ref5","doi-asserted-by":"crossref","unstructured":"MARTINS , J.J.G. 2004 Martins , J. , Uzuneanu , K. , Ribeiro , B. , and Jasasky , O. Thermodynamic Analysis of an Over-Expanded Engine SAE Technical Paper 2004-01-0617 2004 10.4271\/2004-01-0617","DOI":"10.4271\/2004-01-0617"},{"key":"ref6","unstructured":"Turner , J. W. G. , Blundell , D. W. , Larkman , D. B. , Burke , P. , Pearson , R. J. , Richardson , S. , Green , N. M. , Brewster , S. , Kenny , R. G. and Kee , R. J. 2009 Omnivore: an automotive flex-fuel 2-stroke engine with variable compression ratio, variable charge trapping and direct fuel injection Meche.E I. Internal Combustion Engines: Performance, Fuel Economy and Emissions Conference 2009 2009-12-08 - 2009-12-09 London"},{"key":"ref7","unstructured":"MARTINS , J J G 2009 Process for Efficiency Improvement of a 2-Stroke Engine with Rotary Valve on the Exhaust Portuguese Patent n\u00ba103663 9 June 2009 17 July 2009"},{"key":"ref8","doi-asserted-by":"crossref","unstructured":"Issa , R. I. 1986 Solution of the Implicitly Discretised Fluid Flow Equations by Operator-Splitting Journal of Computational Physics 62","DOI":"10.1016\/0021-9991(86)90099-9"},{"key":"ref9","doi-asserted-by":"crossref","unstructured":"Lindemann , F. A. et. al. 1922 Discussion on 'the radiation theory of chemical action' Transaction of the Faraday Society 17 598","DOI":"10.1039\/TF9221700598"},{"key":"ref10","doi-asserted-by":"crossref","unstructured":"Han , Z. , and Reitz , R. D. 1995 Turbulence Modeling of Internal Combustion Engines Using RNG k-\u03f5 Models Combustion Science and Technology 106","DOI":"10.1080\/00102209508907782"},{"key":"ref11","doi-asserted-by":"crossref","unstructured":"Amsden , A. A. 1997 KIVA-3V: A Block Structured KIVA Program for Engines with Vertical or Canted Valves Los Alamos National Laboratory Report No. LA-13313-MS","DOI":"10.2172\/505339"},{"key":"ref12","unstructured":"Heywood , J. B. 1988 Internal combustion engines fundamentals New York McGraw-Hill, Inc."}],"event":{"name":"SAE 2016 World Congress and Exhibition","start":{"date-parts":[[2016,4,12]]},"number":"217486","location":"Detroit, Michigan, United States","acronym":"ANNUAL"},"container-title":["SAE Technical Paper Series"],"original-title":[],"link":[{"URL":"https:\/\/saemobilus.sae.org\/downloads\/papers\/2016-01-1054\/Full%20Text%20PDF","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,8]],"date-time":"2025-10-08T15:13:50Z","timestamp":1759936430000},"score":1,"resource":{"primary":{"URL":"https:\/\/saemobilus.sae.org\/papers\/a-new-rotary-valve-2-stroke-engines-enabling-expansion-2016-01-1054"}},"subtitle":[],"proceedings-subject":"SAE Technical Paper Series","short-title":[],"issued":{"date-parts":[[2016,4,5]]},"references-count":13,"URL":"https:\/\/doi.org\/10.4271\/2016-01-1054","relation":{},"ISSN":["0148-7191","2688-3627"],"issn-type":[{"type":"print","value":"0148-7191"},{"type":"electronic","value":"2688-3627"}],"subject":[],"published":{"date-parts":[[2016,4,5]]},"article-number":"2016-01-1054"}}