The presence of twisted helical flow patterns in the cardiac cavities during ventricular filling and ejection was supposed. This work was intended in order to show that the intraventricular trabeculation plays the determining role in such a flow formation and to find some analytical approaches for its analysis. The morphometric study of human left-ventricular and aortic corrosion casts and dynamic measurement of the aorta by MRI-technique were performed. The data were analysed by means of the "Mathematica'" program. Two groups of trabecules were identified that refer to the inlet and outlet of the ventricular blood flow. The first group consists of trabecules of the free left-ventricular wall. The second group consists of long trabecules going along the anterior left-ventricular wall and intracavital lines of the papillary muscles. Both are twisted clockwise and converge in the flow direction. Each group of trabecules is oriented towards the mitral or aortic valve orifices, correspondingly. It was concluded that the helical trabecular organization acts as flow directing paddles that change their mutual orientation during the cardiac cycle evolution. The reorientation of the flow takes place due to sequential contraction of the ventricular structures. The formalization of trabecular orientation will allow one to calculate improved models of implantable substitutes and auxiliary devices for cardio-vascular surgery.

Basic results are considered of aerohydrodynamic and thermophysical experiments, in which secondary tornado-like jets (TLJ) are revealed and investigated. These jets are self-organized under conditions of flow past surfaces with three-dimensional recesses (dimples) with a second-order curvilinear surface (TLJS – tornado-like jet surface). Exact solutions are given of unsteady-state Navier–Stokes and continuity equations, which describe the TLJ. The impact is considered, which is made on the flow in dimple by forces forming a flow of new type with built-in secondary tornado-like jets. These forces are absent in the case of flow past initially smooth surfaces. The problems are discussed of reducing the aerohydrodynamic drag on the TLJS, of enhancing the heat and mass transfer with the level of hydraulic loss lagging behind the degree of enhancement, of increasing the critical heat loads under conditions of boiling and supercritical flows of continuous medium past the TLJS, of preventing cavitation damage to the TLJS in hydraulic apparatuses, of reducing the adsorption of foreign matter on these surfaces, of reducing the friction between TLJS rubbing against one another, and of raising the efficiency of facilities for tornadolike conversion of energy of renewable low-potential sources. It is demonstrated that the obtained exact solutions of Navier–Stokes and continuity equations provide an adequate model of generation and evolution of swirling flow of blood in human blood circulation system, which enables one to proceed to development of safe and effective devices for substitution of organs in cardiac surgery. An inference is made about the universality of the flow of new type for raising the efficiency of technologies involving flows of various media.

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The vortex heat exchange in turbulent flows around a spherical hole and a transverse trench, identical in depth and in the shape of the middle cross section, on a plane wall has been numerically investigated using multiblock computational technologies. A factorized, implicit multiblock algorithm and a Menter's model of shear-stress transfer were tested in the process of comparative analysis of calculation and experimental data on flows around isolated holes.The problem of intensification of heat exchange in flows around holes is of considerable interest for specialists in thermal physics. In recent years, the geography of investigations on this problem has widened sharply. At present, practically all countries of the world are involved in them. The interest shown in the method of vortex intensification of heat exchange in flows is evidently explained by the fact that this method makes it possible to increase the heat transfer from a wall at low hydraulic losses. However, this process has been predominantly investigated by experimental methods that give no way of obtaining an integral idea of its physical mechanisms. Such an idea can be obtained using numerical-simulation methods, which have been rapidly developing in recent years.The present work continues a series of investigations [1-10] devoted to numerical simulation of the convective heat exchange in turbulent flows of an incompressible fluid around isolated holes and an ensemble of holes of various depth and shape on a plane with account for the blocking of the flow by the walls of a narrow channel. In this case, prominence is given to the interrelation between the restructuring of self-organizing vortex structures and the intensification of heat exchange in the neighborhood of holes.Considerable recent advances have been made in the numerical study of the jet-vortex structures responsible for the vortex intensification of heat exchange in three-dimensional separation flows around holes. An analysis of the evolution of a vortex flow around an isolated spherical hole, included in a narrow channel, on a wall with increase in the depth of the hole has shown that the two-vortex flow in the shallow hole is spasmodically transformed into a single-vortex structure with diagonal transfer of fluid in a deep hole. This transformation is accompanied by a jump-like increase in the heat transfer from both the hole itself and the wake downstream of it. It has been established that such transformation of the near-wall flow and the heat-exchange can also take place in shallow holes if they are asymmetric. One of the technologically simplest holes is a hole representing two hemispheres connected by a cylinder. Such an elongated hole can be arbitrarily oriented relative to an incoming flow. It was positioned at an angle of 45 o to an incoming flow in calculations and experiments. An analysis of flows around spherical and conical holes has shown that the heat transfer in them increases as a result of intensification more rapidly than the hydraulic losses. It has been establis...

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