%0 Journal Article
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%@nexthigherunit 8JMKD3MGPCW/3ETR8EH
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%X This research work brings about additional contribution to validate the ultrasound scattering technique as a nonintrusive probe in the Fourier space for measurements performed in unsteady flows. In particular, this work reports experimental evidence of scattering from a turbulent thermal plume utilized as a testing flow. This technique is based upon the scattering of an ultrasound wave hitting and interacting with an unstable flow. The coupling among the acoustic mode with vorticity and entropy modes is derived from nonlinear terms of NavierStokes and energy equations. Scattering mechanism occurs when characteristic length scales of flows are comparable with wavelength of sound. Thus, it is possible to probe the flow at different length scales by changing the incoming frequency. The results allow verifying some theoretical predictions, such as the existence of a nonscattering angle. It was also observed, that both the phase and the Doppler shift of the Fourier's signal are linear, respectively, with respect to the time and the frequency of the incident wave. The Doppler shift allowed us to determine the advection velocity and has proved to be sensitive to the direction of the wave vector, to the scattering angle and also, we show that it is possible to have both positive and negative angles. The advection velocity increases with temperature and its values are coherent with those obtained with traditional techniques. Broadening and Doppler shift of the scattering signal allowed us to define the turbulence intensity, whose values are in agreement with those found in thermal plumes, where well-known techniques are currently used. This study has shown that the turbulence intensity increases weakly with temperature, nevertheless it seems more sensitive to the size of the structure under observation.
%@mirrorrepository sid.inpe.br/mtc-m19@80/2009/08.21.17.02.53
%8 Feb.
%N 1
%T Data Analysis of Monochromatic Signals from ALLEGRO GW Detector
%@secondarytype PRE PI
%@usergroup administrator
%@usergroup banon
%@usergroup marciana
%@group
%@group
%@group
%@group DAS-CEA-INPE-MCT-BR
%3 magalhaes.pdf
%@secondarykey INPE--PRE/
%@issn 0028-0836
%2 sid.inpe.br/mtc-m19@80/2010/08.02.12.57.37
%@affiliation Instituto Tecnológico de Aeronáutica, Departamento de Física, 12.228-900 São José dos Campos, SP, Brazil
%@affiliation Instituto Tecnológico de Aeronáutica, Departamento de Física, 12.228-900 São José dos Campos, SP, Brazil
%@affiliation Universidade Federal de São Paulo, Prof. Artur Riedel, 275, Diadema, SP 09972-270, Brazil
%@affiliation Instituto Nacional de Pesquisas Espaciais (INPE)
%@affiliation Instituto Federal de São Paulo, Pedro Vicente 625, SP, Brazil
%@affiliation Instituto Federal de São Paulo, Pedro Vicente 625, SP, Brazil
%B Nature
%P 353-356
%4 sid.inpe.br/mtc-m19@80/2010/08.02.12.57
%D 2010
%V 199
%@doi 10.1016/j.nuclphysbps.2010.02.059
%O Proceedings of the International Workshop Light Cone 2009 (LC2009): Relativistic Hadronic and Particle Physics
%A Oliveira, F. G.,
%A Marinho Jr., R. M.,
%A Magalhães, N. S.,
%A Aguiar, O. D.,
%A Frajuca, C.,
%A Pires, R.,
%@dissemination WEBSCI; PORTALCAPES.
%@area CEA