Detuner is a generic term for a

jet engine A jet engine is a type of reaction engine discharging a fast-moving jet (fluid), jet of heated gas (usually air) that generates thrust by jet propulsion. While this broad definition can include Rocket engine, rocket, Pump-jet, water jet, and ...

test cell

exhaust system An exhaust system is used to guide reaction exhaust gases away from a controlled combustion inside an engine or stove. The entire system conveys burnt gases from the engine and includes one or more exhaust pipes. Depending on the overall system ...

muffler. Aircraft jet engine testing facilities typically require a means to vent and dampen the engine exhaust. The engine exhaust flow is "augmented" with a relatively large flow of cooling air induced by a Venturi effect into the exhaust silencing system, so the exhaust muffler is generally referred to as an "augmenter tube," or "detuner" (UK). Interest by Douglas Jack W.Cullum in the noise generated by aircraft engines and propellers led to the design of a silencer for the W2 700 jet engine developed by

Sir Frank Whittle Air Commodore Sir Frank Whittle, (1 June 1907 – 8 August 1996) was an English engineer, inventor and Royal Air Force (RAF) air officer. He is credited with inventing the turbojet engine. A patent was submitted by Maxime Guillaume in 1921 fo ...

and his team at Power Jets Ltd. This original detuner was a straight-through silencer, a simple acoustic tube. A later version consisted of four acoustic sections with a plain entry section inside the test cell, flanged and bolted together, mounted on wheels, and installed on rails to permit fore and aft movement. Each acoustic section consisted of an inner and outer casing: the outer casing was plain mild steel plate and the inner casing was perforated mild steel plate. The cavity between inner lining and outer casing was tightly packed with an acoustic absorbent material known as rock (mineral) wool. Modified versions of the prototype detuner were installed on the

Rolls-Royce Rolls-Royce (always hyphenated) may refer to: * Rolls-Royce Limited, a British manufacturer of cars and later aero engines, founded in 1906, now defunct Automobiles * Rolls-Royce Motor Cars, the current car manufacturing company incorporated ...

jet engine test beds at Clitheroe in Lancashire,

Barnoldswick Barnoldswick (pronounced ) is a market town and civil parish in the Borough of Pendle, Lancashire, England. It is within the boundaries of the historic West Riding of Yorkshire, Barnoldswick and the surrounding areas of West Craven have bee ...

in Yorkshire and Derby, Derbyshire where the jet engine continued development. Derby Test Houses

The development of the detuner was inextricably linked to the development of the jet engine. As the power of the engines increased, new detuners had to be developed to cope with larger and more powerful engines. Test Facility

References

{{reflist *Dousing the Decibels’ Flight Magazine- 5 September 1952 *Jest Test Bed Silencing’ The Aeroplane - 12 December 1952. Printed by Temple Press London *Silencing the Swift’ Flight Magazine - 8 October 1954 *Silencing Pens for Jet Aircraft’ The Engineer, Volume 198 October 8, 1954 *Keeping the big Jets quiet’ BOAC News - 10 June 1960 *Noise Testing at London Airport’ The Times - Thursday 16 June 1960 *The Control of Noise’ Dr B Wheeler Robinson, New Scientist 29 June 1961 *How do you Silence a hi-tech jet engine capable of 160,00 pounds of thrust?’ Article by Oliver Astley Derby Evening Telegraph Tuesday July 8, 2008

External links

"Muffler Silences Jets."
''Popular Mechanics'', February 1955, p. 97.

Cullum Detuners homepage