چكيده به لاتين
Hydrodynamic cavitation is a process in which when a fluid passes through a throat, its pressure is lower than its vapor pressure, it creates bubbles and then creates energy by collapsing the bubbles. In this process, the creation of bubbles due to the reduction of pressure, and then their bursting creates a lot of energy along with free radicals, it increases the speed of chemical reactions and has wide applications in oil and petroleum and wastewater treatment industrial. In the current research, a venturi hydrodynamic cavitation reactor with dimensions optimized by previous studies in this field, which was optimized for Congo red decolorization, with inlet and outlet diameters of 31 mm, throat diameter of 4 mm, throat length of 4 mm, the convergence angle is 22.7 degrees and the divergence angle is 6.5 degrees in order to predict, check and analyze the performance of the mentioned reactor in terms of cavitation under new operating conditions and determine the appropriate operating conditions according to the type of input fluid, CFD simulation done. The results of this simulation were validated with the reported values of the optimized venturi in previous studies and only 2.21% error was obtained. In the upcoming research, we will focus on the effect of temperature, pressure and type of fluid on the performance of the optimized venturi reactor. For the two-phase flow of water, benzene, and fuel oil separately at pressures of 4, 5, and 6 atmospheres and temperatures of 30, 45, and 60 degrees Celsius, water with a density of 980-1004 Kg/m3, benzene with a density of 834-867 Kg/m3, fuel oil with a density of 946-960 Kg/m3 and Methanol with a density of 748-781 Kg/m3 were simulated and the results are presented. This simulation is done with a steady flow three-dimensional model and multi-phase fluid flow with k-ε turbulence model and Schnerr and Sauer cavitation model and pressure based solver in Ansys Fluent software. The results of the simulation clearly show that the increase in temperature has led to an increase in the vapor phase along the venturi throat. Also, increasing the pressure at the venturi reactor inlet will result in an increase in speed, which will lead to a decrease in the cavitation number and an increase in bubbles. It is worth mentioning that due to the existence of fluids other than water in the industry, the performance of the venturi reactor under the passage of fluids such as benzene and fuel oil will require unique operating conditions that have been addressed in the upcoming research and the results of this simulation It shows the effect of fluid type on reactor performance and cavitation rate.
