Results 141 to 150 of about 1,327 (186)

On the Influence of the Molecular Prandtl Number on the Turbulent Prandtl Number

1979
Much more work has been done on the problem of turbulent transfer of momentum in a shear flow than on the problem of turbulent heat transfer. One of the reasons is obviously the fact, that from an experimental point of view informations about velocity-velocity correlations are easier to obtain compared with temperature-velocity correlations.
M. Jischa, H. B. Rieke
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Turbulent Prandtl number in circular pipes

International Journal of Heat and Mass Transfer, 1984
Presentation d'une methode de calcul du nombre de Prandtl pour un ecoulement turbulent dans une conduite circulaire a partir du nombre de Nusselt. Resultats obtenus pour differents fluides a differentes temperatures: eau, CO 2 , glycerol, ethylene ...
A. Malhotra, S.S. Kang
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Prandtl number effects in convective turbulence

Journal of Fluid Mechanics, 1999
The effect of Prandtl number on the dynamics of a convective turbulent flow is studied by numerical experiments. In particular, three series of experiments have been performed; in two of them the Rayleigh number spanned about two decades while the Prandtl number was set equal to 0.022 (mercury) and 0.7 (air).
Verzicco, R., Camussi, R.
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A Reinterpretation of the Turbulent Prandtl Number

Industrial & Engineering Chemistry Research, 2002
The eddy viscosity at any location in fully developed turbulent flow in a round pipe is shown by an exact analysis to be simply the ratio of the shear stress due to the time-averaged turbulent fluc...
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Turbulent Prandtl number in a circular jet

International Journal of Heat and Mass Transfer, 1990
Abstract Measurements of the Reynolds shear stress and heat flux distributions at a number of streamwise stations in a heated circular jet into still air indicate that the flow is approximately self-preserving at x d = 15 . Measurements made with a 120° X-probe are in closer agreement with calculations obtained by integrating the mean ...
L.P. Chua, R.A. Antonia
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Turbulent Thermal Convection at Arbitrary Prandtl Number

The Physics of Fluids, 1962
The mixing-length theory of turbulent thermal convection in a gravitationally unstable fluid is extended to yield the dependence of Nusselt number H/H0 on both Prandtl number σ and Rayleigh number Ra. The analysis assumes a layer of Boussinesq fluid contained between infinite, horizontal, perfectly conducting, rigid plates.
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Prandtl-number dependence of turbulent flame propagation

Physical Review E, 2001
Inertial-range cascade phenomenology is used to predict Prandtl-number (Pr) dependencies of turbulent flame properties. A unified picture of turbulent flame structure and burning velocity is developed that encompasses all Pr regimes. Implications of the analysis for gaseous flames (Pr near unity), autocatalytic fronts in liquids (high Pr), and ...
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Coherent Structures and the Turbulent Prandtl Number

1989
It is experimentally well established that heat spreads faster than momentum in free shear flows |1|. Thus, in the core of a jet, the turbulent Prandtl number Prt is about 0.7. Some measurements suggest that this break-down of the Reynolds analogy (which assumes Prt = 1) may be explained by the role of large-scale structures in the turbulent transport.
M. Favre-Marinet, G. Binder
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A model of the turbulent burst phenomenon: Predictions for turbulent prandtl number

Letters in Heat and Mass Transfer, 1981
Abstract A preliminary analysis is developed coupling surface-renewal and classical ideas which accounts for the fundamental difference between the transport process within the wall region and the turbulent core. It shows that Pr t increases with Pr very near the wall, but decreases with Pr at greater distances from the wall.
L.C. Thomas, M.B. Ibrahim
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Turbulent Prandtl Number in Neutrally Buoyant Turbulent Round Jet

Journal of Engineering Mechanics, 2002
A method which combines two nonintrusive imaging techniques, particle tracking velocimetry and laser induced fluorescence, was used to make simultaneous measurements of velocity and concentration in a neutrally buoyant turbulent round jet. The measurements were made at two different Reynolds numbers (R), 360 and 4,210, at a Schmidt number of 1,930. The
Kuang-An Chang, Edwin A. Cowen
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