Hydrodynamics and Mass Transfer: Numerical Modeling

Abstract

Purpose. Water use systems include a significant number of specialized facilities, the task of which is to implement certain technological processes. These facilities contain a significant amount of equipment used to solve a complex of tasks: water filtration, reagent supply to the mixer, wastewater neutralization, impurity precipitation in settling tanks, air supply to structures for biological water treatment, etc. When designing such equipment or when reconstructing a particular water use facility, it is necessary to determine in advance the efficiency of the equipment proposed by the engineer. Methodology. To solve the hydrodynamics problem – determining the water flow velocity field, an inviscid fluid model is used. The mass transfer process in structures is modeled on the basis of the impurity distribution equation in a continuous medium. The Liebman method is used for numerical integration of the hydrodynamics equation. The splitting scheme is used for numerical integration of the impurity mass transfer equation. Findings. Two numerical models have been developed that allow solving hydrodynamics and mass transfer problems in water use structures in a few seconds of computer time. The Liebman method was used to solve the hydrodynamics problem, which provides a simple software implementation of the numerical model. The splitting method is used to solve the mass transfer problem. Originality. Two numerical models have been developed to solve problems of hydrodynamics and mass transfer in water-use structures. The numerical models take into account the most significant factors affecting the distribution of impurities in structures. The proposed models make it possible to quickly solve problems of hydrodynamics and mass transfer, which is especially important at the stage of design «forecast». Practical value. Numerical models require little time when implemented on low- and medium-power computers. This allows the designer to perform a series of calculations within one hour.