Issue
J. Phys. II France
Volume 7, Number 5, May 1997
Page(s) 801 - 812
DOI https://doi.org/10.1051/jp2:1997152
DOI: 10.1051/jp2:1997152
J. Phys. II France 7 (1997) 801-812

Sound Scattering on a Turbulent, Weakly Heated Jet

A. Petrossian1, 2 and J.-F. Pinton1

1  Laboratoire de Physique, École Normale Supérieure de Lyon CNRS URA 1325, 69364 Lyon France
2  Physics Department, Yerevan State University, 1 Manoukian street, 375049 Yerevan, Armenia

(Received 28 October 1996, revised 22 January 1997, accepted 13 February 1997)

Abstract
We report an experimental study of the scattering of ultrasonic plane waves on a turbulent jet in air (Pr = 0.7). The jet is weakly heated so that the temperature fluctuations act as a passive scalar. In the backscattering geometry one measures the Fourier components of the temperature field $\tilde{T}(q, t)$. The time averaged characteristics are analyzed in detail; in particular we observe a Kolmogorov "-5/3" power law behavior for the passive scalar spectrum in the inertial range of scales. The study of the time fluctuations shows that the histograms of $\tilde{T}(q, t)$ remain close to a Gaussian at all scales.



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