Convergencia numérica de canaleta Parshall para simulación de mezcla rápida con dinámica computacional de fluidos

Abstract

The purpose of this paper is to show the numerical convergence of Parshall flume for the simulation of the rapid mixing required in drinking water treatment plants. The treatment systems include a series of processes such as coagulation, and for this to be carried out efficiently, it depends on the rapid mixing that can be performed by taking advantage of the turbulence caused by hydraulic devices such as the Parshall flume. To carry out the optimization of the rapid mixing units, the flow through the flume must be simulated by stabilizing the variables that the computational model will need. By means of the construction of a three-dimensional CAD model of the flume entered as input data to the OpenFOAM software, the physical domain under consideration will be defined in. stl format. With this established, the correct meshing of the model is developed, which contemplates the design of the finite volume network in which the domain is discretized, and then the solution of Euler equations for viscous fluids and Navier Stokes equations by means of OpenFOAM solvers. After the convergence of the numerical model of the Parshall flume, the different fields of velocity, pressure, turbulence and turbulence energy dissipation continue to be analysed, which will improve the understanding of the hydraulic phenomena present in the fast-mixing unit. In this simulation study with a flow of 13 l/s, the convergence of the iterative solution was achieved in iteration 24401 where the CFD model is stabilized, achieving residuals of 10-2 10-3 of order of magnitude, accepted in the literature to establish that there is a mathematical convergence.