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.Le Chatelier's principle in its traditional formulation states that "if a system in stable equilibrium is subjected to an external disturbance that takes the system away from equilibrium, then the equilibrium will shift in a direction which tends to reduce the effect of the external disturbance" [16].An advantage of this formulation of Le Chatelier's principle is that, within a given model of the system without a detailed analysis of the conditions of dynamic equilibrium of the system's components, it allows one to determine the direction of a relaxation process that tends to reduce the effects of the external change imposed on the system. That is, Le Chatelier's principle serves as a principle of equilibrium shift. In this formulation, Le Chatelier's principle can be used in chemistry to predict the direction of a shift in the dynamic equilibrium of chemical reactions in order to favor the optimization of the yield of products. However, in other fields of natural sciences, this formulation is not efficient, because it contains no stop criterion that would allow judging about the end of this (already chosen) relaxation process. Without this stop criterion for the relaxation process, it is not clear how, within the framework of the model, the limit transition can be performed to a state of stable equilibrium, in which the values of macroparameters are deterministically connected with a given stationary level of the external disturbance.Note that the above-mentioned formulation of Le Chatelier's principle contains important information that the effect of the external cause is reduced when the system reaches a new state of stable equilibrium. This information could be used as a basis for the missing stop criterion if it would additionally contain a value of this reduction when the system reached a state of stable equilibrium. The most interesting fact is that this lacking information on the value of this reduction has long been known and, furthermore, a formulation of Le Chatelier's principle exists [3, p. 22] in which the emphasis is on the decrease in the external effect: "the system tends to such changes that would minimize the external effects." Unfortunately, the former information on Le Chatelier's principle as on the principle of equilibrium s...

The underwater slopes of hydraulic earth structures subjected to the effect of a longitudinal flow are usually protected by a stone revetment obtained by filling stone into the water with subsequent leveling.The shortcomings of this method are: the large consumption of stone, high labor intensity, long construction time, and poor quality and reliability of the revetment.The method of self-placment of stone is free of these shortcomings [i].The essence of the method of self-placement of stone is that in the low-flow period an additional shoulder of soil (sand) with a horizontal berm above the water level is filled to the design outline.Material intended for revetting the slope is placed on the berm. During the flood the revetting material, as the slope and berm are eroded, gradually moves to the slope, forming the revetment.The method of self-placement has been rather thoroughly investigated under laboratory conditions [2]. The main purpose of the experiments was to establish the mechanism of formation of a revetment by self-placement of stone. A generalization of the experimental results made it possible to compile a scheme of formation of the revetment by self-placement of stone ( Fig. i). At flow velocities exceeding the nonerodible for sand, the slope begins to be eroded, but more intensely at the base, and its steepness gradually increases.Erosion occurs with the formation of mobile ridges, collapse of the slope does not occur. On reaching a steepness m~ = 2.5, individual stones begin to move down slope, and each stone rolls into a pit forming at the bottom near it. As the number of stones increases on the slope, the rate of erosion decreases and the height of the ridges decreases.When m 2 = 2, mass movement of the stones downslope begins.The stones, moving downward, wobble, turn, but do not turn over. In the presence of a nonerodible bottom, a part of the stones is placed on the bottom.A steepness m 2 = 2 is preserved until complete protection of slope by stones. Stabilization of the slope occurs as a result of mutual adjustment of individual stones so that the sucking of sand from under ends. The revetted slope remains stable with increase of flow velocity to the noneroding for the revetting material on the slope.Gravel with a size of 3-7 mm was used in the experiments as a model of stone. The thickness of the revetment layer in all experiments was equal to the size of one particle over the entire slope. The maximum density of gravel on the slope was obtained with its six-layer thickness in the fill on the berm.With a two-layer thickness of the gravel layer, the slope is not protected at all.The ratio of the density of placement in the fill on the berm and density of placement on the slope, called the self-placement coefficient, in the experiments reaches k s = 1.5. For sphericla particles the theoretical value k s = 1.2. It is obvious that for material with alarge degree of nonuniformity of the fractional composition, k s = i.O.Experiments completely confirmed the calculation scheme of self-placement (Fig....

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Stream flow under an ice cover is markedly complex and is determined by the difference in the frictional force exerted by the channel bottom and the ice surface on the water. In hydraulic calculations it is important to determine the position in the vertical of the maximum velocity.In the quadratic drag range, in determining the position of the maximum velocity it is desirable to obtain a simple equation for calculation, and for a small difference in roughness of the walls the equation of N. N. Pavlovskii can be used. Dividing the flow at the line of maximum velocity into two independent parts (see diagram) and utilizing the condition of balance of forces for equal motion there can be derived the equationin which C t is the Chezy coefficient, characterizing the complex relation with the velocity v t of the frictional force of dze current on the ice cover, C t = f (nb hi); C 2 is the Chezy coefficient characterizing the complex relation with the velocity v z of the frictional force of the current on the bottom, Cz= f(nz, h~).The relation between the average velocities of the flow in the upper and lower sections can be determined also by a logarithmic equation of the distribution of the velocity in the vertical. Taking %t =0.4, we have v,_._= 1 + 2.5 (C~lC,)

It is shown that correction factors in turbulent motion models can be determined in a way alternative to a calibration method from a synergetic criterion of equilibrium between a body and environment-an extremum of a local effect of counteraction to the integral effect in the relaxation process of body transition into an equilibrium state.