ON CALCULATION OF MAXIMUM SOUND PRESSURE SPECTRUM FROM STATIONARY AND MOBILE JETS

The calculation of the maximum sound pressure spectrum from turbojets of aeroplanes on their take-off trajectory is based on the generalized expression of acoustical power emitted by the fixed or moving axisymmetric jets; it takes account of the laws of spatial distribution of the sound energy and of the generalized characteristics of the linear maximum sound pressure spectrum at a given distance of reference (30 m). The numerical solutions of the equation obtained are facilitated by the use of diagrams and require knowledge of the geometrical and aerodynamic parameters of the jets and also the aeroplane speed. © 1968.