The beginning, laid in the USSR in 1953, of hydraulic stripping of coals and strong rocks in the mining industry, led to a number of domestic and foreign experimental studies of nozzles in order to determine those of their profiles, which provide maximum forces on the bottom hole - preventing the flow.
In the study of stresses in sediments, a thin layer on a metal wall is treated as an elastic medium lying on a perfectly rigid base.
Impulsive loading of the surface of an elastic half-space and "dome-shaped" distributed pressure encountered in the determination of contact problem stresses in hydraulic fracturing of massifs was considered in the works on the basis of solving equations by the method of separation of variables.
The question of sufficient conditions supplementing the necessary general criterion conditions of similarity in hydrodynamic problems is equivalent to the question of the uniqueness of the solution of the system of basic equations.
Mathematical models of the drive of rotary feed mechanisms (RPM) of roller cone drilling machines, necessary for the selection of operational modes of control of drilling processes and design of systems of automatic regulation of its parameters, are poorly studied.
In practice of operation of hydraulic drive systems of mining machines a great role is played by hydraulic shocks arising at switching of its switchgear and often being the cause of failure of elements of hydraulic systems ...
The dynamic character of the action of a hydraulic monitored jet on a monolithic massif is related to the well-known Bernoulli formula for the pressure force of a stationary jet on the plane of an obstacle perpendicular to it...
In the present article with the help of the method of I. G. Bubnov - B. G. Galerkin an establishing (transitional to static) process of deformation of an elastic half-space from the applied to its surface instantaneously and further in time not changing, asymptotically decreasing from the center, axisymmetrically distributed normal load is considered - p.
As is known, the complex mechanism of unsubmerged jets is not sufficiently studied and the results of the corresponding experimental studies are still poorly amenable to hydromechanical interpretation. Under these conditions, the need for practical calculations has led to the necessity of studies designed to develop empirical formulas narrowly limited, private, application area. Such an approach to the study of jets, when used in advance without a sufficiently rigorous hydromechanical justification of the patterns obtained from experiments, only conditionally can be considered correct.
In the design and operation of mine and mine caloriferous installations of great importance are the amount of electricity consumed and the amount of installed power to drive the fan. Let's analyze these data on the example of several institutes of giproshakht.
In the development of scientific bases of hydromechanization of mining works the theory of motion of a free unsubmerged jet plays a great role. There is quite an extensive literature on the structure of the jet leaving the nozzle, instability developing in it, jet decay, influence of conditions preceding its exit, resistance of the surrounding (much less dense) medium and dynamic properties of the jet. Nevertheless, even in the experimental field, the existing data cannot be recognized as exhaustive for the creation of a hydraulic theory of the jet.
