Simulation of Water Flow in a Cavitation Reactor

Abstract

Introduction: Searching for methods to improve the efficiency of water treatment with reagents is quite important in both water conditioning and industrial wastewater purification. Among the technologies providing high efficiency and reducing resource consumption in combination with reagent methods, hydrodynamic cavitation water treatment is of particular interest. The analysis of scientific and technical data made it possible to determine the main indicators of hydrodynamic cavitation water treatment that can affect the efficiency of reagent purification. Extreme parameters occurring during intense cavitation are associated with the formation of high temperatures up to 2000°C and high pulse pressures of 100–1500 MPa in local areas of hydrodynamic systems. In such conditions, the initiation and intensification of the physical and chemical processes of water treatment are observed. Рurpose of the study: Improving the efficiency of existing traditional water purification technologies, allowing to improve its quality at the lowest cost. Methods: To study the parameters affecting water treatment efficiency and occurring with the cavitation flow of water, simulation in Ansys CFX was performed with the use of the finite volume method. The calculation was carried out with account for the turbulent nature of the flow based on the k-ε turbulence model. The cavitation process was calculated with the use of the Rayleigh-Plesset cavitation model. Results: Steam formation in the cavitation reactor promotes sufficiently complete absorption of the gaseous disinfectant by water. An increase in temperature is also considered as one of the factors increasing the efficiency of water treatment with reagents. During cavitation, water temperature increases in local micro-volumes. Thus, to intensify the process, there is no need to heat the entire volume of liquid, and, as a result, the total energy consumption for water treatment is reduced.