Journal ArticleDOI
Turbulent transport of a passive scalar in a round jet discharging into a co-flowing stream
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In this article, the mass transport properties of a round turbulent jet of water discharging into a low velocity co-flowing water stream, confined in a square channel, are investigated experimentally.Abstract:
The mass transport properties of a round turbulent jet of water discharging into a low velocity co-flowing water stream, confined in a square channel, is investigated experimentally. The measurement region is the self-similar range from x/d=70 to x/d=140. Combined laser-induced fluorescence and 2D laser Doppler velocimetry are used in order to measure simultaneously, instantaneously and in the same probe volume, the molecular concentration of a passive scalar and two components of the velocity. This technique allows the determination of moments involving correlations of both velocity and concentration fields, which are necessary to validate the second-order modelling schemes. Both transport equations of Reynolds shear stress uv and turbulent mass flux vc have been considered. In both cases, advection, production and diffusion terms have been determined experimentally. The pressure-strain correlation and the pressure scrambling term are inferred with the help of the budget of Reynolds shear stress and mass turbulent transport equations. Second order closure models are evaluated in the light of the experimental data.
The turbulent Schmidt number is found to be almost constant and equal to 0.62 in the center region and decreases strongly to zero in the mixing layer of the jet. The effects of the co-flow on the turbulent mixing process are also highlighted.read more
Citations
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The saturation of the fluorescence and its consequences for laser-induced fluorescence thermometry in liquid flows
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Potential core lengths of round jets in stagnant and moving environments
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References
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Book
The Properties of Gases and Liquids
TL;DR: In this article, the authors estimate physical properties of pure components and Mixtures and show that the properties of these components and mixtures are similar to those of ideal gases and liquids.
Journal ArticleDOI
Progress in the development of a Reynolds-stress turbulence closure
TL;DR: In this article, the authors developed a model of turbulence in which the Reynolds stresses are determined from the solution of transport equations for these variables and for the turbulence energy dissipation rate E. Particular attention is given to the approximation of the pressure-strain correlations; the forms adopted appear to give reasonably satisfactory partitioning of the stresses both near walls and in free shear flows.
Journal ArticleDOI
Some measurements in the self preserving jet
Israel Wygnanski,H. E. Fiedler +1 more
TL;DR: In this paper, the axisymmetric turbulent incompressible and isothermal jet was investigated by use of linearized constant-temperature hot-wire anemometers and the quantities measured include mean velocity, turbulence stresses, intermittency, skewness and flatness factors, correlations, scales, low-frequency spectra and convection velocity.
Journal ArticleDOI
Transport Equations in Turbulence
Bart J. Daly,Francis H. Harlow +1 more
TL;DR: Turbulence transport equations, describing the dynamics of transient flow of an incompressible fluid in arbitrary geometry, have been derived in such a manner as to incorporate the principles of invariance (tensor and Galilean) and universality as discussed by the authors.
Journal ArticleDOI
Velocity measurements in a high-Reynolds-number, momentum-conserving, axisymmetric, turbulent jet
TL;DR: In this article, the turbulent flow resulting from a top-hat jet exhausting into a large room was investigated and the Reynolds number based on exit conditions was approximately 105 Velocity moments to third order were obtained using flying and stationary hot-wire and burstmode laser-Doppler anemometry (LDA) techniques.
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