Fluid Dynamics & Aerodynamics

Biography

Biography: Olga V. Mitrofanova

Abstract

The present report focuses on the problems of physical and mathematical modeling of large-scale vortex structures as special objects of study of fluid dynamics. The analysis of physical features and theoretical description of helical and swirl flows has been done. Physical and computational experiments to identify the mechanisms of appearance of large-scale vortex structures in channels of complex geometry under condition of the turbulent flows of conductive and neutral fluids have been carried out. The theoretical aspects concerning the modeling of the processes of vortex generation and accumulation of energy by large-scale vortex structures have been considered to predict accidents in engineering systems and natural disasters. It is shown that the topology of the stable form of helical-vortex formations has a structural similarity depending on the vorticity intensity of the fluid motion. This paper presents the results of studies on the solution of problems of the safety improving of power installations and the prevention of emergency modes arising from acoustic and resonant effects, interdependence of large-scale vortex motion with acoustic effects in hydro-mechanical systems and with magneto-hydrodynamic effects in conductive fluids, conditions of formation of large scale vortex and swirl flows in nuclear power installations (in particular, the phenomenon of spontaneous swirling of a flow and the generation of large-scale vortices in the collector systems of the fast neutron reactors), parameters of acoustic oscillations arising during the generation of stable vortex structures (to prevent the development of vibrations) and phenomena of acoustic cavitation and other mechanisms of mechanical energy transformation in high-speed vortex streams. The obtained results are intended both for engineering applications and for the development of simulation methods to predict some hazardous geophysical processes such as hurricanes, tornados, tsunami and changing the direction of ocean currents.