Hidraulički efekti prirodne konvekcije u realnim paralelopipednim rezervoarima izloženim spoljnim uticajima

Abstract

Natural convection in enclosed spaces has been studied for quite a long time in energetics. It emerges in a wide range from the smallest scales (in pipelines, channels, tanks) to the largest ones (atmosphere, molten planet core). The occuring processes depend on geometric relations and temperature of respective surfaces, which defines the type of flow that would occur. A special group of these flows appears when the flow takes place between two parallel plates with different temperatures, most often when the lower plate temperature is higher than that of the upper – a well known case is that of the Rayleigh - Bénard convection. The given examples of natural convection are still based on the generalization of the plates confining the flow being unlimited. In engineering practice, this is surely not the case so that in the proposed research the influence of the side walls to the flow is done, with no idealization of the process and in the real three-dimensional domain. Natural convection has an undeniable effect on the thermal-flow processes in engineering practice. The tanks used in most mobile engineering systems are approximately of parallelopipedic shape. Such tanks may contain all kinds of hydraulic fluids, so that the research done within this dissertation has chosen water, diesel fluid, motor oil, alcohol and air that represent the majority of fluids that can be found in the given tanks. The research done within the dissertation will show the influence of external effects, most of all, of temperature changes upon thermal-flow processes taking place in the given tanks. The obtained results should more closely show the real flow regimes taking place in the given tanks as well as their influence upon the deposition of solid particles that can be found in the given tanks.