Results 181 to 190 of about 2,592 (223)

Isotropic and axisymmetric turbulence of passive scalars

Fluid Dynamics Research, 2000
Summary: A statistical approach to isotropic/axisymmetric turbulence of passive scalars is considered. The scalar transport equation provides Kármán-Howarth-type equations governing the scalar functions that characterize the statistical correlations of flow properties.
Shivamoggi, B. K., Antonia, R. A.
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The Dynamics of Isotropic Turbulence

2015
It has been shown in Chap. 6 how the description of an isotropic turbulent field can be simplified for an incompressible flow. In physical space, only one scalar function \(f(r)\) is necessary to describe the two-point velocity correlations \(R_{ij}({\varvec{r}})\).
Christophe Bailly, Geneviève Comte-Bellot   +1 more
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Behavior of heavy particles in isotropic turbulence

Physical Review E, 2008
The motion of heavy particles in isotropic turbulence is investigated using direct numerical simulation. The statistics related to the velocity and acceleration of heavy particles for a wide range of Stokes numbers, defined as the ratio of the particle response time to the Kolmogorov time scale of turbulence (St=tau_{p}/tau_{eta}) , are investigated. A
Jaedal, Jung, Kyongmin, Yeo, Changhoon, Lee   +2 more
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Homogeneous and Isotropic Turbulence

2015
The study of homogeneous and isotropic turbulence is very rewarding for two reasons. On the one hand, it is possible to do an important part of it analytically, and on the other hand, the smallest turbulent structures in most turbulent flows have an almost isotropic behaviour.
Christophe Bailly, Geneviève Comte-Bellot   +1 more
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Spectrum of Isotropic Turbulence

The Physics of Fluids, 1967
Two expressions are obtained for the turbulent viscosity associated with the transfer of mean-square vorticity across the spectrum. Both involve the three-dimensional energy-spectrum function E and on equating them, a differential equation for the spectrum is obtained. For small wavenumber magnitudes and at high Reynolds number, E = (27/3/3) ε2/3 k−5/3,
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Compressible Homogeneous Isotropic Turbulence

2018
This chapter is devoted to isotropic incompressible turbulence. The main features of related theories are discussed, along with the recent results: energy spectrum and two-point correlations and related models, closures for non-linear terms in both physical and Fourier space, theories for grid turbulence decay including fractal grid case, non ...
Pierre Sagaut, Claude Cambon
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Isotropic Turbulence and Spectra

2011
The knowledge gained from similarity theory is applied in many fields of natural and engineering science, among others, in fluid mechanics. In this field, similarity considerations are often used for providing insight into the flow phenomenon and for generalization of results.
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Temperature structure functions in isotropic turbulence

Physical Review A, 1991
A method of modeling isotropic turbulence with a passive scalar is presented that can derive the high-order temperature structure functions with reasonable asymptotic behavior. As a necessary tool for this purpose, a theory of joint intermittency exponents of the dissipation of turbulent energy and scalar variance is developed, which is led to be ...
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Approximations for Steady-State Isotropic Turbulence

The Physics of Fluids, 1964
The direct-interaction approximation for turbulence maintained by stationary, isotropic, random stirring forces is formulated in the wavenumber-frequency domain. Further, simplifying approximations are made. The final equations involve the wavenumber energy-spectrum, a characteristic correlation frequency for each wavenumber, and a characteristic ...
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Homogeneous Isotropic Turbulence

1977
Many theoretical investigations of turbulence have been developed around the concept of homogeneous, isotropic turbulence — turbulence of which the statistical properties do not vary with position and have no preferred direction. An approximation to such a motion can be obtained behind a grid, such as the one shown in Fig. 21.1, in a wind-tunnel.
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