Ejecting ability of circulating flows of liquid and gas

Abstract

Abstract The process of aeration of liquid plays an important role in many structures and devices. In water-works and hydropower construction during operation of the spillway systems, aeration allows for hydrodynamic and cavitation effects on the elements of the structures to be monitored. Aeration is also used to saturate water with oxygen depending on the purpose of the chemical or biochemical processes in various industries, for example, in fisheries and hydro ecology. Of all known methods the most widespread is the gas-liquid aeration. It allows not only to generate air bubbles, but also to control technological parameters. Various types of circulating flows of liquid and gas, which are swirling flows in circular cylindrical channels, are widely used in various fields of engineering. One of the effects of such flows is the emergence of recirculation areas with pressure in the near-axial zone of the flow below atmospheric one, which makes it possible to eject air into water masses. This feature allows the use of efficient aeration devices based on circulation flows. The report presents the results of physical studies of a complicated flow formed by interacting, oppositely rotating, coaxially located liquid layers. The description of the experimental stand for model studies of such flows is given. Analytical dependences of pressure distribution and specific energy in circulation flow of the viscous liquid are presented. The results of physical modeling to determine the ejection ability of circulating flows, the experimental dependences of the ejection coefficient for different methods of swirling the flow are presented.