Day 4

Welcome back to Day 4. Today we will go even further into the depths and find, where the rubber meets the road (at least mathematically). We will have a special focus on discretization. Why is this important? Did you ever try to solve the fluid dynamic equations for an arbitrary industrial application by hand? Well... In most cases it is a better idea to break down the partial differential/integral equations into "simple" operations (+,-,*,/) and solve them for "small" volumens (yes, the cells in your mesh). This is called discretization. Today you will gain the knowledge, how this works.

We will concentrate on:

Go back to "3 weeks" series.

Discretization

To kick things off, follow this tutorial on discretization and the influence of different schemes on the simulation results. Here the focus is on:

• spatial discretization
• face interpolation
• changing schemes in OpenFOAM
• divergence schemes
• influence of discretization on the simulation results of a passive scalar
• postprocessing

Discretization strategies

In this tutorial you will find strategies on how to improve your simulation results by optimizing the utilized discretization settings. The focus is on

• gradient scheme
• gradient limiter
• convection discretization
• face interpolation
• diffusion discretization

Theory

To conclude this day, in this tutorial you will find an in depth summary of the theory in CFD and also in OpenFOAM. A brief list of the topics covered:

• finite volume method
• CFL number
• linear solvers
• solution methods
• unsteady and steady simulation
• residuals
• boundary and initial conditions