Fundamental Investigation of Noise Generation by Turbulent Jets 570025
EQUATIONS relating to noise outside a turbulent jet to the turbulent velocities inside the jet have been derived making use of Lighthill's suggestion that the actual flow field can be simulated with a stationary field of quadrupoles.
Hot-wire anemometer techniques were applied to a 3V½-in. air jet to measure the turbulent structure of the mixing region. These measurements and the previously derived equations were used to estimate some of the characteristics of the sound field.
The estimated characteristics were found to be in good agreement with the experimentally measured sound field of a full-scale turbojet engine.