Two- and four-stroke engines: Difference between revisions

Revision as of 03:21, 8 July 2024

Revision as of 23:16, 4 October 2024

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* Simplicity of construction<ref name="novenia">[http://www.invenia.es/tech:05_pl_spop_0dwm Invenia] New-generation various fuel forms internal combustion engine – a review from Spain. {{Webarchive|url=https://web.archive.org/web/20080325123047/http://www.invenia.es/tech:05_pl_spop_0dwm |date=2008-03-25 }}</ref><ref name="German">[http://www.bit.or.at/irca/bbsshow8.php?ref1=05%20PL%20SPOP%200DWM&vQuelle=&cc= BBS] A review from Germany. {{Webarchive|url=https://web.archive.org/web/20090129150005/http://www.bit.or.at/irca/bbsshow8.php?ref1=05%20PL%20SPOP%200DWM&vQuelle=&cc= |date=2009-01-29 }}</ref>

The idea was developed at the [[Silesian University of Technology]], Poland, under the leadership of Adam Ciesiołkiewicz.<ref>Journal of KONES Internal Combustion Engines 2002 No. 1-2 {{ISSN|1231-4005}}, the official Polish educational site{{dead link|date=October 2021}}</ref> It was granted the [[patent]] number 195052 by the Polish [[Patent Office]].<ref name="patent">[http://www.uprp.pl/wydawnictwa/wyd/bup_03/bup09_03/bup09_2003.pdf The Polish Patent Office newsletter] {{in lang|pl}} {{Webarchive|url=https://web.archive.org/web/20070125181513/http://www.uprp.pl/wydawnictwa/wyd/bup_03/bup09_03/bup09_2003.pdf |date=2007-01-25}}</ref> The work with the new combustion engine has been done by IZOLING P.W. Company in cooperation with the Silesian University of Technology in Gliwice. Consultations with researchers from Technical University of Kraków were also held. So far, two working engine models have been made. The preliminary model is based on two existing engines (a two-stroke motorbike engine and a four-stroke small machine engine). This model confirms the concept of two- and four-stroke engines' connection. The second model is the functional model.<!-- It realizes the elaborated engine work conception. --> The new solution for a combustion engine was presented during scientific conferences (KONES '2002, Seminary of biofuels 2003, etc.) and in mass media (journals, newspapers, TVP, radio).

=== The M4+2 engine working cycle ===

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The engine is characterized by:

* Extended gas expansion and limited [[exhaust gas]] temperature on the outlet,;

* The variability of the compression ratio and the possibility of changing the compression ratio during the engine work depending on load.

* A beneficial changing of working space during the mixture compression with different crankshafts' polar locations. That makes the pressure forming in the cylinder possible (within reasonable limits).

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Calculations prove the new engine has more favorable parameters and work indicators:

* The increase of engine [[thermal efficiency]] (Although the mechanical efficiency is lesser than a conventional engine)

* Higher total efficiency – efficiency characteristic is more favorable at medium load. It is comparable with the diesel engine efficiency, so the exploitation of fuel consumption is relatively smaller.

* The higher torque and the higher power output compared to the four-stroke SI engine with the same stroke volume

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<!-- Preliminary research shows that the combustion engine has possibility of lean-mixtures combustion (lambda>1). The properties and the possibility of compression ratio change during normal work forecast the possibility of different fuels combustion (like vegetable oils, low-octane petrol, bio – fuels with high stage of vegetable components). The properties and features of new engine show that it can work as SI or diesel engine.

-->

=== Ricardo 2x4 engine ===

The two-cycle modes are currently being researched at [[Ricardo Consulting Engineers]] in the [[United Kingdom|UK]]. The concept consists in switching from one mode to the other depending on the [[Revolutions per minute|rpm]] value. The four-stroke engine is more efficient when running at full throttle, while the opposite is the case for the two-stroke engine. When a small car under heavy load runs at half speed, the engine automatically switches to the two-cycle mode, which is then more efficient. The research on this showed a 27% reduction in fuel consumption.<ref name="genius">[http://www.theengineer.co.uk/Articles/305434/Stroke+of+genius.htm Engineer Online] Stroke of genius [[The Engineer (UK magazine)]]{{dead link|date=October 2021}}</ref><ref name="mit">[http://www.technologyreview.com/Energy/20494/ Nonelectric Hybrid Engines] [[Technology Review]]/[[MIT]] A novel hybrid engine could slash fuel consumption{{dead link|date=October 2021}}</ref>