Рассматривается влияние внешнего волнового воздействия на фильтрацию жидкостей из капилляров в окружающую капилляры ткань и из ткани в капилляры. Установлены два механизма увеличения скорости фильтрации: нерезонансный, связанный с несимметричностью изменения проницаемости поверхностного слоя капилляров и окружающей капилляр ткани на смежных полупериодах волновых воздействий и резонансный, связанный с увеличением перепада давлений, обусловленного пульсовой волной в капилляре, синхронного и синфазного с ним повышения проницаемости, обусловленного волновыми воздействиями. Установленные эффекты могут найти применение в медицине для интенсификации транскапиллярного обмена и микроциркуляции в кровеносной системе.

Based on the results of experimental observations, mathematical models of the impact of the factors under study on repression-wave colmatation are obtained. The values of the factors are established at which mud solutions acquire a higher resistance to sedimentation of the solid phase due to its concurrent dispersion increasing the efficiency of colmatation of absorbing hole sections.

На основании результатов экспериментальных наблюдений получены математические модели влияния исследуемых факторов на параметры репрессионно-волновой кольматации. При этом установлены значения исследуемых факторов, при которых глинистые растворы приобретают более высокую устойчивость к седиментации твердой фазы за счет ее попутного диспергирования, что повысило эффективность кольматации поглощающих интервалов в стволе скважины.

The influence of external wave action on the filtration of the fluid from capillaries into the tissue surrounding the capillaries and from the tissue into the capillaries is considered. Two mechanisms for increasing the filtration rate are established: nonresonant, associated with the asymmetry of the change in the permeability of the capillary surface layer and the tissue surrounding the capillary at adjacent half-periods of wave actions, and resonant, associated with an increase in the pressure drop caused by a pulse wave in the capillary, and a synchronous and in-phase increase in permeability due to wave actions. The established effects can find application in medicine for the intensification of transcapillary exchange and microcirculation in the circulatory system.

The results of experimental studies of a new type of wave hydromassagers capable of operating both in water and in air ensuring their convenience are presented. Such devices create three-dimensional (in particular, spiral) waves with amplitudes and frequencies of velocities and pressures of a wide range, including rarefaction zones on the treated surface. This enhances the physiotherapeutic effect. The data obtained can be used in the design of wave hydromassagers and other hydrodynamic oscillation generators for various purposes.

To carry out studies of periodic mechanical effects on people, a new type of massagers, wave hydromassagers, capable of creating 3D (in particular, spiral) waves in hydrodynamic flows in a wide range of amplitudes, frequencies, and pressures, including those with decompression zones on the treated surface, is considered. The main types of wave hydromassagers are discussed. The results of experimental study and mathematical modeling of wave hydromassagers of one of the developed types, namely, jet-vortex ones, are presented. It is shown that the best agreement between the calculated and experimental data is obtained using the large eddy simulation (LES) method. The data can be used in the design of wave hydromassagers and other hydrodynamic oscillators for various purposes.

In this paper, we establish the scientific basis for the generation of intense hydroacoustic waves in a liquid as a result of the detonation of a stoichiometric mixture of hydrogen and oxygen. The idea of the possibility of carrying out this process with the help of a deep-water electrolyzer, which was confirmed experimentally, is expressed. The processes of combustion and detonation of a stoichiometric mixture of hydrogen and oxygen surrounded by a liquid medium and the initial conditions for an increase in pressure and temperature at the interface between detonation products and a liquid medium at the moment of explosion decay, providing the emergence and propagation of a hydroacoustic wave in a liquid medium, were studied using mathematical modeling methods. The dependence of the peak pressure of the resulting wave, the duration of its positive phase, and the duration of the first wave period on the volume of hydrogen and oxygen, pressure, and other parameters is estimated. The possibility of using the established effect to enhance oil production in oil and gas production is shown.

An approach to the study of wave processes in the human cardiovascular system is presented in order to identify the constituent components in the complex signal of the pulse pressure wave—direct and reflected waves. This makes it possible to calculate the pulse wave propagation time and velocity, which are indicators that play an established role in the diagnosis and prognosis of cardiovascular diseases. Testing of the approach is based on a combination of methods for measuring the pulse wave with subsequent mathematical processing of empirical data and methods for direct numerical modeling of hemodynamic processes in the arterial tree.

The results of a numerical study of the thermal and acoustic energies released during the collapse of a single spherical cavitation bubble in water at a pressure of 10 bar and a temperature of 20°С are given. In the model used, we take into account the thermal conductivity of the vapor in the bubble and the surrounding liquid, heat transfer, evaporation/condensation on the surface of the bubble, and the fluid compressibility. The conversion of mechanical energy into heat due to the fluid viscosity is not accounted for. When the bubble collapses, the energy of acoustic radiation due to radial pulsations of the bubble is shown to be approximately nine times greater than the energy spent on heating the liquid. The value of this energy is proportional to the cube of the initial bubble radius.

Stirring processes in oscillatory-type plants are considered. The influence of the shape of the moving element on the quality of stirring is studied using computational modeling methods. Further, the power consumed by the plant is assessed. Similarity criteria that allow a well-founded approach to scaling the stirring plants of the type in question are applied to the processes under consideration.

The results of computer modeling of mixing in a system of mobile coaxial cylinders are presented. Detailed spatial-temporal descriptions of the processes are obtained, and the principal structures in the flow field are determined. On the basis of the analysis of the singular points of the fluid vector field, a way of rotor profiling is proposed. The similarity numbers are introduced, which allow us to proceed from laboratory stand installations to real industrial devices.

Представлены результаты компьютерного моделирования перемешивания в системе подвижных коаксиальных цилиндров. Получены детальные пространственно-временные картины протекающих процессов и определены основные структуры в поле течения. На основе анализа особых точек векторного поля скоростей жидкости предложен способ профилирования ротора. Введены числа подобия, использование которых позволяет осуществить переход от лабораторных стендовых установок к реальным производственным аппаратам.