Proceedings of the USSR Academy of Sciences · 1941 · 4.5K citations · 0 references
Natural SciencesMathematicsPhysicsFluid DynamicsFluid MechanicsCompressible FlowHydrodynamic StabilityIncompressible FlowTurbulenceTurbulent FlowTurbulent TransportCompressible TurbulenceIncompressible Viscous FlowLocal StructureReynolds NumberReynolds Number ScalingTurbulent Vortex DynamicsVortex Dynamics In Turbulence
§1. We shall denote by uα ( P ) = uα ( x 1, x 2, x 3, t ), α = 1, 2, 3, the components of velocity at the moment t at the point with rectangular cartesian coordinates x 1, x 2, x 3. In considering the turbulence it is natural to assume the components of the velocity uα ( P ) at every point P = ( x 1, x 2, x 3, t ) of the considered domain G of the four-dimensional space ( x 1, x 2, x 3, t ) are random variables in the sense of the theory of probabilities (cf. for this approach to the problem Millionshtchikov (1939) Denoting by Ᾱ the mathematical expectation of the random variable A we suppose that ῡ 2 α and (d uα /d xβ )2― are finite and bounded in every bounded subdomain of the domain G .