Search results
Results from the WOW.Com Content Network
Acoustic sources within the "jet pipe" also contribute to the noise, mainly at lower speeds, which include combustion noise, and sounds produced by interactions of a turbulent stream with fans, compressors, and turbine systems. [1] The jet mixing sound is created by the turbulent mixing of a jet with the ambient fluid, in most cases, air.
[1] [2] This is used to calculate the total acoustic power of the jet noise. The law reads as =, where is the acoustic power in the far-field, is the proportionality constant (or Lighthill's constant),
Rolls-Royce Conway Mk508 (1959) with hush kit attached. The most common form of hush kit is a multi-lobe exhaust mixer.This device is fitted to the rear of the engine and mixes the jet core's exhaust gases with the surrounding air and a small amount of available bypass air.
This gives a less effective exhaust gas velocity (lower jet noise) and therefore lower efficiency, and can be achieved in the landing phase by using a variable area final nozzle to rematch the fan. Furthermore, acoustic treatment in the intake and exhaust ducting can minimize turbomachinery noise.
The exhaust thrust from a jet engine is equal to exhaust mass flow times exhaust velocity, i.e., Thrust = ṁv, while the energy to make that thrust is given by Energy = 1/2mv 2. A mixer helps reduce the fastest exhaust velocities from the core of the engine, while making the average exhaust velocity faster, producing more thrust with the same ...
Download QR code; Print/export ... Pages in category "Aircraft noise" ... Jet noise; N. Night flying restrictions; No Aircraft Noise; S.
Talk: Jet noise. Add languages. Page contents not supported in other languages. ... Download QR code; Print/export Download as PDF; ... Wikipedia® is a registered ...
Aeroacoustics is a branch of acoustics that studies noise generation via either turbulent fluid motion or aerodynamic forces interacting with surfaces. Noise generation can also be associated with periodically varying flows. A notable example of this phenomenon is the Aeolian tones produced by wind blowing over fixed objects.