The article presents the theoretical research of the use of swirling flows with reverse jets and with developed precessing vortex core in cavitators and other devices. While describing the motion of the vortex core in the free swirling jet of the fluid it is necessary to take into account that according to the experimental data the vortex core can swirl along the length of the jet and moves around the jet axis in the zone between the area of reverse flows and the boundary outer layer. In this case, it is the vortex core which is under the influence of the basic swirling flow. Herewith, it is necessary to take into account that due to commensurate sizes of the vortex core and the jet, the impact on the core will be different owing to non-uniform distribution of speeds in the jet itself. On the basis of the known formulas, the authors have deduced the improved theoretical dependence of the degree of flow swirl on the flow rate, the vortex core vibration frequency and structural parameters under the conditions of the consistency of swirling flow itself. The theoretical dependence shows that the degree of flow swirl is directly proportional to the precessing vortex core vibration frequency and inversely proportional to the square of mass flow rate. Thus, ensuring the consistency of the swirling flow with varying flow-rate requires the corresponding change of the swirl degree or the influence on the frequency of vibrations of the precessing vortex core. On the basis of the deduced theoretical dependences, the authors have developed and implemented in the computer programs the following calculations: the dependence of the coefficient of the flow swirl on the vortex core vibration frequency; the simulation of the precession of the vortex core in the swirling flow; the research of speed fluctuation in the swirling flow; speed fluctuation during the interaction of swirling jets.

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The article considers the use of a jet pump design with separate workflows for the production of high-viscosity oil. The authors have developed an improved design of a jet well unit with separate workflows, in which the working fluid, moving through the inner annulus, reaching the pump housing, is divided into two streams. A portion of the working mixture - 40% (depending on the cross section of the nozzle of the twisting chamber) enters the twisting chamber of the hydrodynamic cavitator, via which the working fluid passes, creating gas bubbles. These bubbles flake under the action of external pressure at the outlet of the chamber when the liquid passes through a stepped diffuser. The second portion of the working mixture - 60% (depending on the cross section of the jet nozzle) enters the pump nozzle, where flowing at high speed, forms a zone of reduced pressure, resulting in the mixture and oil from the subpacker enter the mixing chamber of the device. We have considered the conditions that can provide the effect of gushing, taking into account the fact that with the use of jet devices can achieve this effect. There may be two cases: 1) the extraction of fluid from wells is limited; 2) the extraction of fluid from wells is unlimited. The initial data, technological parameters and the sequence of their determination are given for the variant when light oil is used as a working liquid, and the working pressure of the surface power plant is not set. Determining the technological parameters of the well unit is a solution to the direct problem, and then - the reverse one. The improved method for calculating the technological parameters of a jet well unit with separate workflows, the design of which has no analogues in Ukraine, is proposed. This technique has been tested during industrial tests of a prototype of an equipment set for the extraction of high-viscosity oils. The method of operation of the pumping-ejector downhole jet unit with a hydrodynamic pulsator for the extraction of high-viscosity oils is protected by a patent of Ukraine.