Acoustic Imaging of Aircraft Wake Vortex Dynamics

Abstract

The experience in utilizing a phased microphone array to passively image aircraft wake vortices is highlighted. It is demonstrated that the array can provide visualization of wake dynamics similar to smoke release or natural condensation of vortices. Examples on how the technique has been integrated with other data to address some of the research issues in wake vortices are documented. These topics include the initial vortex spacing characterization, collaboration with simultaneous pulsed Lidar data to provide a more complete understanding of vortices at a late stage in their evolution, and correlation between atmospheric turbulence with the time-scale involved for vortices developing into a very contorted state. In addition, the paper provides a comparison between the vortex tracks as inferred from their acoustics characteristics vs. those detected from the velocity field (i.e., pulsed Lidar). A preliminary attempt is also made to examine the global link between wake vortex sound and vortex circulation, suggesting that there could be a power law relationship between the two datasets.

Using Multilateration Data in Probabilistic Analysis of Wake Vortex Hazards for Landing Aircraft

“…Some examples of wake measurements that use light (specifically, a lidar-light detection and ranging-instrument) were given by Dasey et al (11) and Chalson et al (12). An example of wake measurements that use sound was given by Wang et al (13).…”

Atmospheric Effects on Microphone Array Analysis of Aircraft Vortex Sound

“…The sound speed can be obtained from knowledge of the temperature via ideal gas assumption, which is sufficient for as long as periods of severe weather conditions are excluded. As a part of the overall wake acoustics study, extensive meteorological data have been collected at the Denver International Airport during summers of 2003 2,6 and 2005. For the present paper, sample time-averaged data from the 2005 test will be used.…”

“…A non-traditional application of phased microphone arrays has recently been extended to the area of aircraft wake vortices. In particular, there is an ongoing effort to study the viability of using phased arrays to passively detect and track aircraft wake vortices [1][2][3][4][5][6] near airports in order to increase safety as well as more efficiently utilize existing runways. Such arrays and the associated signal processing are designed on the basis of ray theory in an ambient medium.…”

Algoritmos eficientes para estimação de imagens acústicas.

“…Imagens acústicas são ainda utilizadas na indústria em aplicações como: distribuição de ruído em túneis de vento devido ao fluxo de ar [24,25]; medição de ruído gerado por turbinas de avião [26]; medição de ruído gerado por turbinas de vento [27]; e medição de ruído e detecção de turbulências de aviões em vôo [28,29].…”