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A Townend ring is a narrow- chord cowling ring fitted around the cylinders of an aircraft
Chapter 5: High-speed Cowlings, Air Inlets and Outlets, and Internal-Flow Systems: The ramjet investigation
Although superior to earlier cowlings, and uncowled engines in terms of drag and cooling, above the NACA cowling was more efficient and soon replaced it in general use.
Examples of aircraft with Townend rings include the
The Spotters Glossary
* * * {{Aircraft components Aircraft propulsion components
A Townend ring is a narrow- chord cowling ring fitted around the cylinders of an aircraft radial engine
The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders "radiate" outward from a central crankcase like the spokes of a wheel. It resembles a stylized star when viewed from the front, and is ...
to reduce drag and improve cooling.
Development
The Townend ring was the invention of Dr.Hubert Townend
Hubert is a Germanic masculine given name, from ''hug'' "mind" and ''beraht'' "bright". It also occurs as a surname.
Saint Hubertus or Hubert (c. 656 – 30 May 727) is the patron saint of hunters, mathematicians, opticians, and metalworkers. ...
of the British National Physical Laboratory in 1929. Patents were supported by Boulton & Paul Ltd in 1929. In the United States it was often called a "drag ring". It caused a reduction in the drag of radial engines and was widely used in high-speed designs of 1930–1935, before the long-chord NACA cowling came into general use. Despite suggestions of it exploiting the Meredith effect, low airspeeds, low temperature differences and small mass flows make that unlikely, particularly when combined with the lack of flow control as the air exits the cowling.Becker, J.; ''The high-speed frontier: Case histories of four NACA programs, 1920–1950'', SP-445, NASA (1980)Chapter 5: High-speed Cowlings, Air Inlets and Outlets, and Internal-Flow Systems: The ramjet investigation
Although superior to earlier cowlings, and uncowled engines in terms of drag and cooling, above the NACA cowling was more efficient and soon replaced it in general use.
Examples of aircraft with Townend rings include the Boeing P-26 Peashooter
The Boeing P-26 "Peashooter" was the first American production all-metal fighter aircraft and the first pursuit monoplane to enter squadron service with the United States Army Air Corps. Designed and built by Boeing, the prototype first flew in ...
, the Vickers Wellesley
The Vickers Wellesley was a medium bomber that was designed and produced by the British aircraft manufacturer Vickers-Armstrongs at Brooklands near Weybridge, Surrey. It was one of two aircraft to be named after Arthur Wellesley, 1st Duke of ...
, the Fokker D.XVI and the central engine on the Junkers Ju 52
The Junkers Ju 52/3m (nicknamed ''Tante Ju'' ("Aunt Ju") and ''Iron Annie'') is a transport aircraft that was designed and manufactured by German aviation company Junkers.
Development of the Ju 52 commenced during 1930, headed by German aero ...
/3m.
Notes
References
External links
The Spotters Glossary
* * * {{Aircraft components Aircraft propulsion components