Multiphase Models Training Course, ANSYS Fluent

Description

Comprehensive Multiphase Models Training Course

Multiphase flows involve two or more phases: liquid, gas, and solid. These flows are complex and can be challenging to model accurately. Fluent is a computational fluid dynamics (CFD) software package that can be used to simulate multiphase flows.

Fluent offers several different models for simulating multiphase flows, including the Volume of Fluid (VOF), Eulerian, Mixture, and Wet Steam models.

The VOF model simulates flows with two or more immiscible fluids, such as oil and water. It tracks the interface between the two fluids and can be used to simulate a wide range of multiphase flows, such as droplet and bubble formation.

The Eulerian model simulates flows with a single fluid containing dispersed particles, such as a gas with solid particles. It tracks the motion of the particles and can be used to simulate flows such as dust clouds and sprays.

The Mixture model simulates flows with two or more miscible fluids, such as air and water vapor. It tracks the motion of the fluids and can be used to simulate flows such as fog and steam.

The Wet Steam model simulates flows with a single fluid containing both liquid and vapor phases, such as steam. It tracks the motion of the liquid and vapor phases and can be used to simulate flows such as boiling and condensation.

In summary, Fluent offers several different models for simulating multiphase flows, including the VOF, Eulerian, Mixture, and Wet Steam models. Each model is designed to simulate a specific type of multiphase flow and can be used to accurately model a wide range of multiphase flows. The Comprehensive Multiphase Flow Training Course will teach you how and where to use them.

Training Course Syllabus

This course contains video lessons and final projects to get a certificate after finishing the course.

Chapter 1: Introduction to Multiphase Flows and their Applications

In the first chapter, we will discuss the basics of Multiphase flows and explain what a multiphase flow is. We will then briefly introduce each of the VOF, Eulerian, Mixture, and wet steam models and bring some examples of their applications in real life or industry. This chapter contains the following subsections:

• Overview of Multiphase flows
• Classification of Multiphase flows
• Multiphase flow regimes
• Eulerian-Lagrangian vs. Eulerian-Eulerian approaches
• VOF model and its applications
• Eulerian model and its applications
• Mixture model and its applications
• Choosing among Eulerian, Mixture, and VOF
• Summary

Chapter 2: VOF Multiphase Model

This chapter will cover the basics and physics behind the VOF model. You will first be familiarized with different options and sub-models of the VOF model and some tips and tricks on using them. Thus, based on the taught topics, we will provide practical examples and solve realistic problems using the VOF model. This section contains the following sub-lessons:

Lesson 1

In this lesson, you will first see a general introduction to the VOF Multiphase model. Then an overview of available simulation techniques and sub-models of the VOF in ANSYS Fluent is explained. This section contains the following subsections:

• VOF applications & applicability
• VOF general settings
• Implicit vs. Explicit formulations
• Available discretization methods
• Body force formulation
• Open channel BC
• Interface modeling
• Level set method
• Surface tension modeling
• Mass transfer mechanisms

Lesson 2

In this lesson, we present a simple, practical example to you. This problem examines the effect of surface tension on flow formation. Namely, we aim to simulate a real-life problem of microfluidic droplet generators.

They are devices used in the biomedical engineering field for quantifying the volume of fluid into micrometer-sized spherical droplets for different types of analyses. You can see how the definition of surface tension will cause a phase to take up a completely different form from its initial state.

Lesson 3

In this lesson, we present a different example from the previous example. This time we are focusing on a very large-scale fluid domain. We will consider a large fluid where multiple sub-oceanic volcanic mountains are placed. The scenario is that the water adjacent to these mountains will reach a boiling state and evaporate due to the volcanic activity of the sub-oceanic mountains.

The formed vapor bubbles will then reach the surface of the water, where the wavy surface will be disrupted due to the motion of vapor bubbles, rupturing the interface of air and water.

Chapter 3: Eulerian Multiphase Model

This chapter will provide an overview of the Eulerian model, including its different options and sub-models. Additionally, we will offer some advice on how to use them. We will provide practical examples and use the Eulerian model to solve real-world problems to demonstrate the concepts. The topics covered in this chapter include:

Lesson 1

In this lesson, you will first see a general introduction to the Eulerian Multiphase model and an overview of available simulation techniques and sub-models of the Eulerian in ANSYS Fluent. This section contains the following subsections:

• Eulerian model applications & applicability
• Regime transition modeling
• AIAD submodel
• GENTOP submodel
• Boiling model
• Interfacial area concentration VS. Algebraic interfacial area
• Applicable forces
• Turbulent interaction & models
• Euler-Granular model
• Summary

Lesson 2

In this lesson, we present a practical example to you. We will examine the boiling phenomenon in a 2D cylinder (axisymmetric rectangle) and try to observe the generated vapor’s motion.

You will see how to enable the basic RPI boiling model and set up a proper boiling simulation by enabling the mandatory forces and their respective models. We will also show you some tips on obtaining correct numerical results from this simulation, as the boiling simulations are generally a bit tricky to handle.

Lesson 3

In this lesson, we present a different example from the previous example. This session will investigate the granular material behavior inside a bio-reactor. We will show you how to set up the proper conditions for granular matter and the available settings and models for granular flows.

Lesson 4

In this lesson, we will delve deeper into the simulation of granular flows by providing an example of packed bed flows. Packed bed flows are fixed regions of solid matter. Here, you will see how the packed bed region, simulated through a granular flow model, can filter another normal granular flow.

This type of application is named the cake filtration process in the industry, where a layer of solid (accumulated particles) accrues on the filter (packed bed region).

Chapter 4: Mixture and Wet Steam Multiphase Models

This chapter will review the fundamentals and science behind the Mixture and Wet Steam models. You will be introduced to the various options and sub-models of the Mixture and Wet Steam models and some helpful hints on how to use them.

Using the Mixture and Wet Steam models, we will then use the topics we learned to provide practical examples and solve real-world problems. This section includes the following sub-lessons:

Lesson 1

In this lesson, you will first see a general introduction to the Mixture and Wet Steam Multiphase models and an overview of available simulation techniques and sub-models of the Mixture and Wet Steam in ANSYS Fluent. This section contains the following subsections:

• Introduction
• Mixture model
• Equations
• Assumptions and Restrictions
• Applications
• Wet steam model
• Assumptions and Restrictions
• Summary

Lesson 2

In this lesson, we will teach you how to simulate the practical problem of cavitation on a boat propeller. The cavitation phenomenon can wear and erode the surface of propellers or pump blades, leading to their destruction sooner than the predicted time.

Hence, by simulating this phenomenon, engineers can alter their design to prevent such incidents from happening. In this session, you learn how to apply the cavitation model using the Mixture multiphase model and how to apply correct boundary conditions to employ this model.

Lesson 3

In this lesson, we present another realistic industrial problem: the formation of water liquid droplets inside a converging-diverging nozzle. The Wet steam model can be used to predict the formation rate of water droplets as the supersaturated dry vapor passes through the throat of a converging-diverging nozzle.

As the supersaturated dry vapor passes through the neck of the nozzle, a sort of shock is applied to the fluid stream, causing the dry vapor to condense into liquid droplets. This phenomenon is studied extensively for many applications such as power plants, biomedical, and food industries.