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

Description

Volume Of Fluid (VOF) Multi-phase ANSYS Fluent CFD Simulation Training Package for BEGINNER Users (Part-II)

This training package includes 10 practical Multi-phase Volume of Fluid (VOF) exercises using ANSYS Fluent software. MR CFD suggests this package for BEGINNER users who tends to learn the simulation process of multi-phase problems without any strong background.

Spillways

Suppose any obstacle is placed on the path of the fluid flow. In that case, it causes the fluid level to rise behind it and increase its velocity, which eventually leads to fluid overflowing over the obstacle. These obstacles are regarded as spillways. Spillways have different uses depending on their shape and are mostly used in civil engineering

Project number 1 is an ogee spillway CFD simulation. Since the channel uses two different flows, the two-phase flow model is used. The two-phase VOF (volume of fluid) model is used in this simulation so that the water is defined as the primary phase, and the air is defined as the secondary phase. The purpose of the present study is to investigate water flow behavior after passing through an ogee spillway in the presence of airflow.

In project number 2, a two-dimensional simulation of a stepped spillway is presented. The volume of fluid (VOF) model is activated for two phases of air and water and the standard k-e model with the use of standard wall function is exploited for fluid flow analysis.

In project number 3, the two-phase flow of water and air flowing over an ogee spillway is simulated. The water will enter the computational domain with a mass flow rate of 60 tons/s, and it flows over the spillway. The standard k-epsilon model is exploited to solve fluid flow equations, and the VOF multiphase model is used to investigate the motion and interaction of the existing phases.

FREE SURFACE (Water Flow)

In project number 4, the two-phase flow inside an open channel with roughness in its middle section is simulated. The water flow enters the channel with a mass flow rate of 32 Kg/s. The k-epsilon equation with scalable wall functions is used to solve and analyze fluid flow.

Project number 5 simulates a counterflow in a canal. This work aims to investigate the type of fluid flow behavior when exposed to a flow in the opposite direction. In this simulation, water flows from the canal into a rectangular section horizontally. At the same time, another flow of water from a pipe lying on the floor of the same canal, horizontally but in the opposite direction of the initial flow into the canal.

In project number 6, the separation of laminar fluid flow from a surface that is easily seen in a natural waterfall is investigated and analyzed. This separation occurs only due to gravity and the difference in height between the two surfaces. Water enters the fluid domain with a mass flow of 20 Kg/s and falls when the lower bed is finished, converting into a waterfall. K-epsilon and implicit volume of fluid (VOF) models are activated to analyze this flow.

In project number 7, a two-phase flow of air and water around a bridge’s pillars is investigated. The simulation is done using the VOF model for the two phases of air and water. The standard k-e model using standard wall functions is also applied for solving the turbulent flow.

Sloshing (Volume of Fluid)

In project number 8, the transitional motion of a cube containing water and air is investigated. The interaction of water and air inside the cube is modeled using the Volume of Fluid (VOF) multi-phase approach. Cube accelerates in the X direction with an acceleration equal to 5 m/s2, while gravitational acceleration affects the multi-phase entity in the –Y direction. This project investigates the simplified sloshing effect in fluid containers where a situation similar to the one studied here can occur due to the acceleration of the carrier vehicle.

Injector

Project number 9 is going to simulate an injector. The Multi-Phase model, which consists of air and water flows, is used. Water flows through three curved ducts into a reservoir that only has airflow inside its space. The curved structure of the ducts and the cone-shaped state on the air-filled tank distributes the water flow vortices into the injector, thereby discharging the water out of the surroundings of the cylindrical chamber (near the chamber wall) of the injector.

Cohesion & Adhesion (Volume of Fluid)

Project number 10 simulates the effect of cohesion and adhesion on a fluid. In this project, it is assumed that there is a T-shaped computational domain; So that the fluid flow enters from the bottom and exits from the top. Also, since this simulation is necessary to define two air and water phases, the multi-phase flow model is used. The multi-phase model used in this simulation is the VOF model; Because this model can distinguish the interface between two fluids.