PROBABILISTIC NATURE OF TURBULENT FLOW AND CLOSURE OF EQUATIONS DESCRIBING THIS FLOW.

An explanation of turbulence as a physical outcome of the non-uniqueness of four-dimensional solutions of the Navier-Stokes equations is suggested. It follows from this that it is necessary (and possible) to introduce an additional probabilistic measure for describing the ensemble of possible random flows that arise with uniquely-defined boundary and initial conditions. The use of this measure requires an additional generalization of the existing fundamental empirical laws of mechanics. The principle of maximum stability of probabilistic characteristics of the system's motion is postulated as such a generalization.