ОСОБЕННОСТИ ГЕМОДИНАМИКИ В СТРУКТУРНО-РАЗЛИЧНЫХ ВНУТРИОРГАННЫХ АРТЕРИАЛЬНЫХ БИФУРКАЦИЯХ СЕРДЦА ЧЕЛОВЕКА, ВЫЯВЛЯЕМЫЕ С ПОМОЩЬЮ ЧИСЛЕННОГО МОДЕЛИРОВАНИЯ

Aim. Сheck the hypothesis about the connection between the type of dichotomy and the peculiarities of blood movement in structurally different bifurcations of the intraorgan arterial bed of the human heart using numerical modeling. Materials and methods. The results of morphometry of the real arterial bed of the heart were used. To simulate unsteady laminar flow, we used the solution of the complete system of Navier-Stokes’s equations, obtained using an implicit difference scheme in the ANSYS package. Results. It was found that dichotomy (bifurcation) of the first type (complete asymmetry) increases the intensity of flow rate fluctuations and the maximum flow rate and decreases the dynamic viscosity of blood in the larger branch. A quasi-stationary flow is formed in the smaller branch. Dichotomy (bifurcation) of the second type (lateral asymmetry) reduces the maximum flow rate and the value of dynamic viscosity in all branches. Dichotomy (bifurcation) of the third type (unilateral symmetry) increases the maximum flow rate and decreases the dynamic viscosity. Dichotomy (bifurcation) of the fourth type (complete symmetry) reduces the maximum flow velocity, deforms the velocity profile, and significantly increases blood viscosity. Moreover, the zone with increased viscosity extends from the flow core to almost the entire flow area. Conclusion. The simulation results allow us to assert a different functional role of arterial dichotomies (bifurcations) of structurally different types. After passing through various types of dichotomies (bifurcations), the blood flow acquires unified properties necessary for the flow in the hemomicrocirculatory section of the bed. The revealed features must be considered in the numerical modeling of the structure of the intraorgan arterial bed of the human heart and intra-arterial hemodynamics.