Editing Aircraft engine (section)

===Piston-turbofan hybrid===

At the April 2018 [[ILA Berlin Air Show]], [[Munich]]-based research institute [[:de:Bauhaus Luftfahrt]] presented a high-efficiency composite cycle engine for 2050, combining a [[geared turbofan]] with a [[piston engine]] core.<!--<ref name=Flight24apr2018>-->
The 2.87 m diameter, 16-blade fan gives a 33.7 ultra-high [[bypass ratio]], driven by a geared low-pressure turbine but the high-pressure compressor drive comes from a piston-engine with two 10 piston banks without a high-pressure turbine, increasing efficiency with non-stationary [[Isochoric process|isochoric]]-[[isobaric process|isobaric]] combustion for higher peak pressures and temperatures.<!--<ref name=Flight24apr2018>-->
The 11,200&nbsp;lb (49.7&nbsp;kN) engine could power a 50-seat [[regional jet]].<ref name=Flight24apr2018>{{cite news |url= https://www.flightglobal.com/news/articles/hybrid-geared-fan-and-piston-concept-could-slash-fue-447955/ |title= Hybrid geared-fan and piston concept could slash fuel-burn |date= 24 April 2018 |author= David Kaminski-Morrow |work= Flightglobal}}</ref>

Its cruise [[Thrust specific fuel consumption|TSFC]] would be 11.5 g/kN/s (0.406&nbsp;lb/lbf/hr) for an overall [[engine efficiency]] of 48.2%, for a burner temperature of {{cvt|1700|K|C}}, an [[overall pressure ratio]] of 38 and a peak pressure of {{cvt|30|MPa|bar}}.<ref>{{cite web |url= https://www.bauhaus-luftfahrt.net/fileadmin/user_upload/CCE_Data_Sheet.pdf |title= Composite Cycle Engine concept technical data sheet |publisher= Bauhaus Luftfahrt}}</ref>
Although engine weight increases by 30%, [[Fuel economy in aircraft|aircraft fuel consumption]] is reduced by 15%.<ref>{{cite web |url= https://www.bauhaus-luftfahrt.net/en/research/energy-technologies-power-systems/the-composite-cycle-engine-concept/ |title= The composite cycle engine concept  |publisher= Bauhaus Luftfahrt}}</ref>
Sponsored by the [[European Commission]] under Framework 7 project {{abbr|LEMCOTEC|Low Emission Core Engine Technologies}}, Bauhaus Luftfahrt, [[MTU Aero Engines]] and [[GKN Aerospace]] presented the concept in 2015, raising the overall engine pressure ratio to over 100 for a 15.2% fuel burn reduction compared to 2025 engines.<ref>{{cite journal |url= https://www.researchgate.net/publication/278674579 |title= A Composite Cycle Engine Concept with Hecto-Pressure Ratio |date= July 2015 |doi= 10.2514/6.2015-4028 |journal= AIAA Propulsion and Energy Conference |author= Sascha Kaiser|isbn= 978-1-62410-321-6 |display-authors=et al}}</ref>