Simultaneous characterization of temperature and ve lo ci ty profiles using time reversal: Numerical study of free convection - Archive ouverte HAL Access content directly
Journal Articles EPL - Europhysics Letters Year : 2001

Simultaneous characterization of temperature and ve lo ci ty profiles using time reversal: Numerical study of free convection

G Bouchet
GEP
A Maurel

Abstract

– We present an acoustical method, based on time reversal, for simultaneous characterization of temperature and velocity profiles. The method is numerically validated in a case of free convection; the acoustic propagation is obtained from calculations of ray propagation and the convective flow is described by analytical profiles or by fields stemmed from numerical simulation. The ray theory approximation, used to solve the inverse problem, is discussed. Introduction. – Most of the usual techniques for temperature measurement are local and intrusive (hot-wire probe, hot-film sensors, thermocouples). Some optical techniques such as low-contrast shadowgraphy, visualization with thermal camera or induced fluorescence measurement are examples of non-intrusive methods but can be used only for translucid fluids. Furthermore, simultaneous measurement of the velocity field is not possible, or requires the use of another technique. Among these techniques, acoustic waves provide a direct, non-intrusive and non-localized way of probing hydrodynamic flow fields. Several approaches have been proposed in the literature, e.g. ultrasound scattering [1, 2] or tomography [3]. When the acoustic wavelength is small compared with the characteristic length of the flow and for small Mach numbers, the description of the sound flow interaction is restricted to geometrical acoustics; in this context, an ultrasonic technique, based on the time reversal process, has been developed recently to study the structure and dynamics of localized vortices [4, 5]; the presented work extends this method by including a simultaneous measurement of a temperature profile. The aim of this paper is to develop and to numerically validate the method, that can be used as an investigation tool on an experimental setup .

Dates and versions

hal-01447039 , version 1 (26-01-2017)

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G Bouchet, A Maurel. Simultaneous characterization of temperature and ve lo ci ty profiles using time reversal: Numerical study of free convection. EPL - Europhysics Letters, 2001, 53 (5), pp.584 - 590. ⟨10.1209/epl/i2001-00192-1⟩. ⟨hal-01447039⟩
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