AdvancedTopic 83 of 105Thermodynamics & Fluids
Computational fluid dynamics
Numerically solves flow equations on a mesh.
In depth
CFD discretises the flow domain into cells and solves conservation equations by finite volume methods. Workflow: geometry, mesh, physics models, boundary conditions, solver, post-processing, verification, validation. Used for aerodynamics, combustion, heat transfer and HVAC.
Key points
- Mesh independence study
- Turbulence model choice
- Convergence monitoring
ExampleCFD predicts the drag of a car before wind tunnel tests.
CFD lets engineers see and test flows before building, which saves time and money in aircraft, cars, buildings and process equipment.
What is Computational fluid dynamics?
Numerically solves flow equations on a mesh.
Why is it important to understand computational fluid dynamics?
CFD lets engineers see and test flows before building, which saves time and money in aircraft, cars, buildings and process equipment.
What are the steps in a CFD study?
Define the geometry, generate a mesh, set the physical models and boundary conditions, solve, and then verify and validate the results.
What is mesh independence?
A check that refining the mesh no longer changes the key results significantly, which shows the solution is not limited by discretisation.
How is Computational fluid dynamics used in practice?
Typical applications include optimising the shape of a car body to reduce drag, checking airflow in a data centre to avoid hot spots and predicting the performance of a pump impeller before manufacture.
What should I learn before Computational fluid dynamics?
Study "Turbulence modelling" first (topic 82 of 105 in Thermodynamics & Fluids). It covers the groundwork this topic builds on.
What are the key points of Computational fluid dynamics?
Mesh independence study. Turbulence model choice. Convergence monitoring.
Can you give an example of Computational fluid dynamics?
CFD predicts the drag of a car before wind tunnel tests.
What comes after Computational fluid dynamics?
The next topic is "Conduction", which builds directly on this one.
How difficult is Computational fluid dynamics?
It is classed as Advanced in Thermodynamics & Fluids (topic 83 of 105). It is an advanced topic. It assumes you are comfortable with the intermediate topics in Thermodynamics & Fluids.