Fast Numerical simulations of 2D turbulence using a dynamic model for Subgrid Motions

We present numerical simulation of 2D turbulent flow using a new model for the subgrid scales which are computed using a dynamic equation linking the subgrid scales with the resolved velocity. This equation is not postulated, but derived from the constitutive equations under the assumption that the non-linear interactions of subgrid scales between themselves are equivalent to a turbulent viscosity.The performances of our model are compared with Direct Numerical Simulations of decaying and forced turbulence. For a same resolution, numerical simulations using our model allow for a significant reduction of the computational time (of the order of 100 in the case we consider), and allow the achievement of significantly larger Reynolds number than the direct method.Comment: 35 pages, 9 figure

Training of the Educators of Preschool Educational Institutions to the Authenticity Formation of the Preschoolers

The development of the personality-oriented model of the Ukrainian education system based on the principle of child-centeredness, maximum consideration of the abilities, needs and interests of each child, its age-specific features of physical, mental and mental development actualizes the problem of the formation and development of authenticity of preschoolers. The essence of the author's technology of authenticity facilitation of the preschooler's personality as a system of scientifically substantiated procedures for the gradual development of the educational process in the unity of content, principles, methods, forms, organizational and pedagogical conditions for the interaction of its subjects, the purpose of which is the ability of the preschooler's personality to live in harmony with its inner world, to act without changing your true "I". The technology is aimed at helping each child to realize itself as a self-worth, knowledge of its capabilities and natural potential in all spheres of life. The totality of the motivational-value, cognitive, operational and reflexive-personal criteria and their corresponding indicators for diagnosing the level of readiness of teachers of pre-school education institutions to form the authenticity of pupils are presented. The results of approbation of the author's elective course for the system of postgraduate pedagogical education "Theoretical and practical bases for the authenticity formation of preschoolers" are presented for the training of teachers of pre-school institutions for the effective implementation of this process

A model differential equation for turbulence

A phenomenological turbulence model in which the energy spectrum obeys a nonlinear diffusion equation is presented. This equation respects the scaling properties of the original Navier-Stokes equations and it has the Kolmogorov -5/3 cascade and the thermodynamic equilibrium spectra as exact steady state solutions. The general steady state in this model contains a nonlinear mixture of the constant-flux and thermodynamic components. Such "warm cascade" solutions describe the bottleneck phenomenon of spectrum stagnation near the dissipative scale. Self-similar solutions describing a finite-time formation of steady cascades are analysed and found to exhibit nontrivial scaling behaviour.Comment: April 10 2003 Updated April 22 2003, 9 pages revtex4, 9 figures Added some figures, additional references and corrected typo