ESDU 82027 B ADD-1983 Estimation of lateral attenuation of air-to-ground jet or turbofan aircraft noise in one-third octave bands Addendum Estimation of sideline noise in subjective noise metrics
ESDU 82027 gives a graphical method@ also implemented as a Fortran program (ESDUpac A8727) on a disc (uncompiled) in the software volume@ for estimating the free-field values of one-third octave band lateral attenuation. Lateral attenuation is defined as the difference between the under-the-flightpath and sideline free-field levels where the propagation distance of the two sound levels is the same. The range of applicability includes sideline noise-levels for turbo-fan and turbo-jet powered aircraft with either rear fuselage or underwing mounted engines when the elevation angle of the aircraft@ relative to an observer at the sideline location@ is greater than five degrees@ the wind speed is less than 6 m/s (20 ft/s) and there are no temperature inversion. The use of the graphs and program is explained by means of a worked example that also illustrates the format of the input and output. An addendum discusses the estimation of sideline noise in subjective noise metrics.
ESDU 82027 B ADD-1983 history
1983ESDU 82027 B ADD-1983 Estimation of lateral attenuation of air-to-ground jet or turbofan aircraft noise in one-third octave bands Addendum Estimation of sideline noise in subjective noise metrics