Simplified permeable surface correction for frequency-domain Ffowcs Williams and Hawkings integrals

A Comparison of Ffowcs Williams-hawkings Solvers for Airframe Noise Applications

AIAA 99-0231 Simulation of Acoustic Scattering from a Trailing Edge

Three model problems were examined to assess the diiculties involved in using a hybrid scheme coupling ow computation with the the Ffowcs Williams and Hawkings equation to predict noise generated by v ortices passing over a sharp edge. The results indicate that the Ffowcs Williams and Hawkings equation correctly propagates the acoustic signals when provided with accurate ow information on the i...

Aeroacoustic Analysis of a Simplified Landing Gear

A hybrid approach is used to investigate the noise generated by a simplified landing gear without small scale parts such as hydraulic lines and fasteners. The Ffowcs Williams and Hawkings equation is used to predict the noise at far-field observer locations from flow data provided by an unsteady computational fluid dynamics calculation. A simulation with 13 million grid points has been complete...

AIAA 99-1802 Computational Aeroacoustic Analysis of Slat Trailing-Edge Flow

An acoustic analysis based on the Ffowcs Williams and Hawkings equation was performed for a high-lift system. As input, the acoustic analysis used unsteady ow data obtained from a highly resolved, time-dependent, Reynolds-averaged Navier-Stokes calculation. The analysis strongly suggests that vor-tex shedding from the trailing edge of the slat results in a high-amplitude, high-frequency acousti...

Approximation of High Frequency Acoustic Wave Surface Integrals

This paper is concerned with the efficient evaluation of some highly oscillatory surface integrals, arising from boundary integral methods for high frequency acoustic scattering in three dimensions. The performance of standard quadrature schemes deteriorates as the frequency of the incident wave increases. We present ideas for improving the evaluation of such highly oscillatory integrals. Intro...