Le Chatelier’s principle and its adaptation for closure of averaged equations of hydrodynamics

A generalized formulation of Le Chatelier's principle is offered, which allows considering the latter as a general physical law of shift and equilibrium in open systems. Application of the generalized formulation to the "kinematic effect of pressure-free flow" allows deriving a rule to calculate the local effect of counteraction to the integral effect in the relaxation process of transition of a nonstationary turbulent flow to the stationary one. In the regime with stationary motion, the local effect of counteraction to the integral effect reaches its maximum under given and constant external conditions. The condition of local effect maximum is used for closure of the equation of the plan velocity diagram. An example is given that confirms the theoretical consideration.[PUBLICATION ABSTRACT]