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Common Questions and Answers (view source)
Revision as of 01:30, 13 April 2022
, 01:30, 13 April 2022→Airplane Design: Add What are the tradeoffs between inline and radial engines? Section
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|text=The employment of a reduction gear secures better propeller efficiency by reducing the speed of the propeller. Further, on air transport ships the practise [sic] adds to passenger comfort by reducing propeller noise.<ref>{{cite magazine |date=November 1930 |title=Reduction Gear Drive for Slower Propeller Speeds |url=http://archive.org/details/aerodigest1719unse/page/n397 |magazine=Aero Digest |access-date=14 March 2022}}</ref>}} | |text=The employment of a reduction gear secures better propeller efficiency by reducing the speed of the propeller. Further, on air transport ships the practise [sic] adds to passenger comfort by reducing propeller noise.<ref>{{cite magazine |date=November 1930 |title=Reduction Gear Drive for Slower Propeller Speeds |url=http://archive.org/details/aerodigest1719unse/page/n397 |magazine=Aero Digest |access-date=14 March 2022}}</ref>}} | ||
=== What are the tradeoffs between inline and radial engines? === | |||
Inline and radial engines each have their own benefits and certain countries and military branches tended to have their own reasons for preferring one over the other.{{efn|For example, the U.S. Navy used almost exclusively radial engine aircraft during World War II.}} | |||
On the one hand, inline engines have less drag, increasing the speed of the airplane.{{efn|Technically, the reduction in drag is not so much the result of a smaller frontal area, but instead the lack of an air pressure drop due to airflow through the cowl.<ref>{{cite book |last1=White |first1=Graham |title=The Piston Engine Revolution |date=2011 |publisher=Museum of Science and Insdustry |location=Manchester |page=283 |url=http://fredstarr.com/wp-content/uploads/13.-Pratt-and-Whitney-R4360-White.pdf |access-date=13 April 2022 |chapter=Pratt & Whitney’s R-4360}}</ref>}} However, it was impossible to sufficiently cool the rear cylinders because the airflow was blocked by the ones in front of them.{{efn|As radial engines increased in size from two to four rows of cylinders towards the end of the war, they started to encounter the same problems with cooling. The Pratt & Whitney R-4360 solved this with a “twisted” cylinder layout and a complicated series of seven plenum chambers to precisely direct the airflow.<ref>{{cite book |last1=White |first1=Graham |title=The Piston Engine Revolution |date=2011 |publisher=Museum of Science and Insdustry |location=Manchester |page=284 |url=http://fredstarr.com/wp-content/uploads/13.-Pratt-and-Whitney-R4360-White.pdf |access-date=13 April 2022 |chapter=Pratt & Whitney’s R-4360}}</ref>}} Therefore, inline engines needed a liquid cooling system. This added additional complexity to the engine. In addition, if the liquid cooling system was to fail for any reason – say, due to loss of coolant from battle damage – the engine would quickly overheat and seize. In contrast, aircraft with radial engines were known to return to base with entire pistons shot away.<ref>{{cite book |last1=Brulle |first1=Robert V. |title=Angels Zero: P-47 Close Air Support in Europe |date=2000 |publisher=Smithsonian Institution Press |location=Washington |url=http://books.google.com/books?id=36VVCgAAQBAJ |access-date=13 April 2022}}</ref><ref>{{cite web |title=397th Fighter Squadron Photo Hendricks Album Page |url=http://www.368thfightergroup.com/397-photo-Hendricks-w.html |website=368th Fighter Group |access-date=13 April 2022}}</ref> | |||
=== What is the difference between a rotary and radial engine? === | === What is the difference between a rotary and radial engine? === | ||