The spatial variation in vector acoustic intensity has been calculated between 100 and 3000 Hz near a high-performance military aircraft. With one engine of a tethered F-22A Raptor operating at military power, a tetrahedral intensity probe was moved to 27 locations in the geometric near and mid-fields to obtain the frequency-dependent intensity vector field. The angles of the maximum intensity ...

Acoustic shocks have been previously documented in high-amplitude jet noise, including both the near and far fields of military jet aircraft. However, previous investigations into the nature and formation of shocks have historically concentrated on stationary, ground run-up measurements, and previous attempts to connect full-scale ground run-up and flyover measurements have omitted the effect o...

This paper describes a method for determining a semi-empirical, equivalent simple-source model that accounts for the sound radiation in the vicinity of a high-performance military aircraft. The characteristics of the equivalent source are guided by previously reported observations of jet noise, namely that the strengths of the partially correlated sources are distributed asymmetrically. The par...

Beamforming techniques for aeroacoustics applications have undergone significant advances over the past decade to account for difficulties that arise when traditional methods are applied to distributed sources such as those found in jet noise. Nevertheless, successful source reconstructions depend on array geometry and the assumed source model. The application of phased-array algorithms to grou...

Coanda Effect in Mechanical ventilators: Named after Henri Marie Coanda (June 7, 1886 – November 25, 1972) was a Romanian inventor, aerodynamics pioneer and the patent holder of the modern jet aircraft. The secret of the fluidic flip is a phenomenon known as the Coanda effect. This is a relatively new discovery previously applied in the fields of aerodynamics and jet engine design. When a jet o...

The influence of ground reflections on the measurement of aircraft engine exhaust noise is examined in this paper. A series of experiments were performed in the UCI aeroacoustic facility of supersonic jet noise with and without a ground plane in close proximity to the jet. Thus the effect of the ground plane on the radiated noise was isolated. Additionally, a computational model for the phenome...

A model of a high subsonic jet with a nearby array of exible, aircraft-type panels is studied numerically in two dimensions. The jet is excited by a limited duration, spatially localized starter pulse in the potential core. The long time evolution of unsteady disturbances in the jet, the responses of the panels and the ensuing radiation are computed. The results show that the spectral response ...