Prediction and measurement of airframe noise on a generic body

Determination of Absolute Levels from Phased Array Measurements Using Spatial Source Coherence

“…This behaviour is in good agreement with the curve obtained by Brooks et al 8 , although in the present case their assumption that the -6-NLR-TP-2002-226 source length is much smaller than the distance to the array is not satisfied (both are 0.6 m). The ACF is also similar to the calibration function found by Ostertag et al 10 for similar conditions. The shape of the curve can be qualitatively understood from the fact that the scan levels for a group of incoherent sources are equal to the sum of the scan levels from the individual sources.…”

“…It was found that both peak and integrated response levels varied significantly as a function of phase and coherence level between the two sources. Ostertag et al 10 investigated trailing-edge noise from a flat plate and determined both theoretically and experimentally an array transfer function relating the levels in the acoustic source plots to absolute sound levels in the farfield. Good agreement between the measured and predicted array calibration function was found.…”

The Prediction of Airframe Noise and Comparison With Experiment

“…Agreement was obtained with the formulation given in equation (1). In addition, measurements of the trailing-edge scattering noise have been made by Brooks and Hodgson [5] and more recently by Ostertag et al [15], con"rming the result given in equation (1). 4.…”

Efficient evaluation of three-dimensional Helmholtz Green's functions tailored to arbitrary rigid geometries for flow noise simulations

“…al. [8] in 2000, of Hu [9] in 2005 and of Takaishi [10] 2007. In these works, the numerical method is not thoroughly described and a standard BEM (not accelerated) is used.…”