Day 7

Welcome back to Day 7. Today we will make another big step in the direction of real life problems by learning about turbulence modeling. Most of the fluid dynamic problems are turbulent and it is of utmost importance how to model it and how to include the models into you simulation setup. Today we will cover

• steady-state turbulence modeling
• transient turbulence modeling
• Reynolds-Averaged Navier-Stokes equations
• Large Eddy Simulations
• initial and boundary conditions
• case setup

Go back to "3 weeks" series.

icoFoam and pisoFoam by Håkan Nilsson

To kick the day off, this tutorial gives a compact explanation of a laminar solver as well as a turbulent solver and the difference between them. The focus is on:

• icoFoam
• pisoFoam
• the PISO algorithm
• write statements
• inclusion of turbulence modeling

Stationary turbulence modeling (RAS)

This tutorial gives you a step by step guideline for the steady-state simulation of a simple 2D case. Here you will learn the basics of RAS turbulence modeling and the steps needed to include a given model into your simulation. The pdf version can be found here. Here you will learn about:

• steady-state turbulence modeling
• Reynolds-Averaged Navier-Stokes equations
• RAS models
• case setup
• boundary and initial conditions
• postprocessing

Transient turbulence modeling (RAS,LES)

This tutorial continues to guide you through the simple 2D case. This time you will consider the case to be transient. Also you will try out both URANS and LES models for the simulation. With this information you will be able to correctly choose the model for your own simulation. The pdf version can be found here. The topic here are:

• transient turbulence modeling
• URANS models
• Large Eddy Simulations
• case setup
• boundary and initial conditions
• postprocessing

The DrivAer case

Finally. This is a very cool case. Here you can test all the knowledge you gained so far by applying it in this case, where you will simulate the flow around a car. In particular, you will consider the following steps:

• meshing
  • blockMesh
  • snappyHexMesh
  • mesh quality
• turbulence modeling
• boundary conditions
• numerics
• functionObjects

End of Day 7

We arrived at the end of Day 7. Now you are very close to simulating your own real-life problem. We hope, that you are still having fun and see you tomorrow on Day 8, where we will continue talking about turbulence modeling. Until tomorrow!