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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 ca ...
to reduce drag and improve cooling.
Development
The Townend ring was the invention of Dr. Hubert Townend of theBritish
British may refer to:
Peoples, culture, and language
* British people, nationals or natives of the United Kingdom, British Overseas Territories, and Crown Dependencies.
** Britishness, the British identity and common culture
* British English, ...
National Physical Laboratory in 1929. Patents were supported by Boulton & Paul Ltd
Boulton & Paul Ltd was a British general manufacturer from Norwich, England that became involved in aircraft manufacture.
Jeld Wen Inc. bought Boulton & Paul (along with another joinery company John Carr) from the Rugby Group plc in 1999 to ...
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
The NACA cowling is a type of aerodynamic fairing used to streamline radial engines installed on airplanes. It was developed by Fred Weick of the National Advisory Committee for Aeronautics (NACA) in 1927. It was a major advance in aerodynamic ...
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 We ...
, 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 Aeros ...
/3m.
Notes
References
External links
The Spotters Glossary
* * * {{Aircraft components Aircraft propulsion components