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ôÁÔÁÒÓÔÁÎ, 9-15, ëÁÚÁÎØ 420021, òïóóéñ
e-mail:
Rashidma@mail.ru
This paper deals with fundamental properties of turbulent motion.
Undoubtedly that specific character of turbulence consists in the loss of
individuality turbulent formations during their evolution. Nevertheless, this
feature still does not have an adequate description in the formalism of
existing models. Given paper construct required behavior by introducing new
turbulent mixing mechanism. For developed turbulent motion, such mechanism is
redused to ensemble of turbulent trajectories that present evolution of
hydromechanical variables.
The description uses multimode princnple that represents hydromechanical
variables of the steady turbulent flow as finite sums, named modes. For
instance, velocity distribution presents by
(1)
where õ – physical space coordinates, y – vector
mode amplitude,
- covectors that perform vector of mode
amplitudes into physically observable quantity. Representation (1) defines hydromechanical variables as fields of vector bundle, with base given by
physical space and fibre presented by the values of mode amplitudes. This
bundle becomes phase space of turbulent evolution. Projection of marked above
trajectories into base creates visible picture of turbulence.
Equations of mode amplitude
evolution defined by Pfaff’s system
(2)
Objects
and
define connection and vertical vector field of
phase space respectively. System (2) implied non-complete integrable. A set of all one-dimensional integral
varieties of this system is considered as an ensemble of turbulent
trajectories. Along these trajectories, mode evolution is completely defined by
initial data. Substitution of a concrete trajectory in (1) will define
development of the appropriate hydromechanical variable only along chosen base
curve. Hence, evolution of all hydromechanical variables will be divided into
layers.
Non-integrability of (2) and non-zero curvature of bundles connection are interpreted as a spatial heterogeneity of turbulent regimes. The number of modes presented the number of freedom degrees of turbulent regime together with marked above objects defines the turbulent structure. Example of such structure with three freedom degrees that average flow presented by the simple shift and pulsation’s of Lorenz’s attractor type is constructed.
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