Volume of Fluid (VOF), Package for Intermediate, Part 2

Description

Multi-phase Volume Of Fluid (VOF) – ANSYS Fluent Training Package, 10 Practical Exercises for INTERMEDIATE Users

This CFD training package is prepared for intermediate users of Ansys Fluent software in the Volume of Fluid (VOF) Multiphase area. You will learn and obtain comprehensive training on how to simulate medium projects. The achieved knowledge will enable you to choose the most appropriate modeling approaches and methods for applications and CFD simulations.

This package trains the necessary proficiency you will require to start doing average computational fluid dynamics (CFD) Multi-phase VOF simulations on your own using Ansys Fluent software. Qualified training movies and comprehensive CFD concepts explanations, including setup, solution, results, and all perspectives of carrying out CFD simulations in Ansys Fluent.

Civil Structures

Spillways are structures used to pass through excess water and floods from the top to the bottom of the dam. In fact, spillways are structures with a certain height that discharge excess water when the water’s height exceeds its height. Project number 1 simulates the flow of water through a spillway. Since the modeled fluids are water and air, the two-phase flow model is used. To define the two-phase flow in this simulation, a two-phase VOF (volume of fluid) model is used.

Project number 2 simulates the water flow on an overflow that enters the pond. There is an ogee overflow in the current simulation that leads to a pond. In this simulation, two types of models are defined, in one of which, water flows as a free surface flow to the overflow and then flows into the pond; While in another, the water flows under pressure on the overflow and flows into the pond. Therefore, for both cases, a two-phase VOF flow model is used; So that the primary phase (air) and the second phase (water) are defined.

In project number 3, a Numerical simulation of the lifting dam has been performed. The VOF model is used to simulate two fluid phases, and the purpose of this project is to investigate the changes in the free surface of the fluid over time. Two models are reviewed in this project. In the first model, the flow continues its path after crossing the dam, but in the second model, it encounters an obstacle.

In project number 4, the hydraulic jump of water flow is analyzed. The VOF approach is utilized to simulate the water flow inside ambient air efficiently. Hydraulic jump is of great importance in agricultural applications and open channel flows where water flow, after a certain distance which can be solved using the analytical equation, undergoes a significant decrease in velocity and increase in flow height. The present work analyzes water flow with two different mass flow inlets, 50 and 80 kg/s.

Separator (volume of fluid)

In project number 5, separating the liquid phase from the gas using a horizontal cylindrical separator is investigated. A multi-phase VOF model is activated to simulate two phases of oil and hydrogen sulfide inside the separator. The mixture of oil and gas (with mass flow rates of 3kg/s and 0.15kg/s, respectively) enters the separator and since the oil is heavier than the gas, it settles down while the gas phase exits from the top outlet

Project number 6 simulates the collision of air and water flow within a separator chamber. In this model, a cylindrical separator chamber is designed whose interior space is full of water. Since this modeling has two phases, the multi-phase model should be used. For this reason, the VOF multiphase model is used in this modeling also, the effect of surface tension between the two phases is defined and the amount of surface tension between the two phases of the water and air is defined as 0.072 N.m-1.

Mixer

In project number 7, a mixer tank is modeled, and the effect of its rotating impeller on the mixing procedure is investigated. The simulation uses the VOF model for the three phases of air, water, and salt. The k-epsilon model is applied for solving the turbulent flow inside the tank. MRF model is also used to model the rotation of the impeller.

Distillation

Project number 8 simulates the two-phase flow of air and water in a distillation column tray. In tray towers, the process of separating the material takes place. His work does not simulate heat transfer and the process of evaporation and distillation. Since the present model consists of two phases of air and water, the multi-phase VOF model has been used.

Ejector (volume of fluid)

In project number 9, the two-phase flow of vapor and liquid ammonia in a two-phase ejector has been simulated. The VOF multi-phase model for two phases of liquid ammonia and vapor ammonia has been used to investigate the phase interactions. The liquid ammonia will enter the computational domain through the primary inlet with a pressure of 9MPa and a temperature of 393K. This flow will induce the vapor ammonia to exit the ejector and liquid ammonia.

Cavitation

Project number 10 simulates the water flow in a water jet. Since there is a possibility of pressure drop in this model, the cavitation phenomenon has been investigated because this phenomenon occurs when the fluid pressure drops to its vapor pressure. Therefore, the model of two-phase VOF flow and mass transfer between two phases of water and water vapor is defined as cavitation at a vapor pressure equal to 3540 Pascal. The present work aims to investigate the changes in the volume fraction of water and water vapor phases.