Computational fluid dynamics

Part of the Wikiversity Division of Fluid Mechanics, Division of Applied Mechanics, School of Engineering and the Engineering and Technology Portal

CFD simulation of aerodynamics of potentially innovative transportation.

Objectives

Introduces novice learners to applying computational fluid dynamics (CFD) appropriately, instilling confidence that their computational results are reliable. Focus will be on:

• Computation of fluid dynamics using open-source software (OpenFOAM).
• Analysis of computational results within data-friendly ecosystem (Python).
• Validation & Verification of computational results.

CFD applications

• Fuel efficiency
• Fire modelling
• Climate change
• More listed on CFD Online.

Introduction

NASA researchers are studying wake vortex with a variety of tools, from supercomputers to wind tunnels to actual flight tests in research aircraft. Their goal is to understand the phenomenon then use that knowledge to create an automated system that could predict changing wake vortex conditions at airports to increase flight safety.

Computational fluid dynamics (CFD) is a branch of fluid mechanics that uses sophisticated software to predict fluid flows.

Everyday computers are used to routinely run this software. This software involves calculations which solves complex mathematical equations that can only be done via methods such as iterative (recursive) algorithms.

With modern computers, better fidelity (or reduced computing times) can be achieved. Especially when horizontal scaling of computing resources is used (such as used in folding@home).

CFD relies on some mathematical & discretisation techniques to be able to make the equations governing fluid motion solvable on a computer. Review this quick-and-dirty introduction to the basics underlying CFD for an overview of these techniques.

Conceptual review

Suggestion to review of the above conceptual material then consolidate these by explaining what each particular technique represents. In other words, what does each step mean and/or do?

1. Finite-volume method.
2. Iterative solving.
3. Convergence.
4. Grid sensitivity.
5. Turbulence modelling.

Practical review

Suggestion to check out a tutorial introducing OpenFOAM. This demonstration will give you an overview of the CFD process. Focus will be on:

1. Linux environment.
2. Basic setup of 'case'.
3. Mesh quality.
4. Boundary conditions.
5. Computation using 3 different meshes.
6. Analysis of the computational results.

Further learning

Other helpful material include:

• YouTube | Fluid Mechanics 101: lecture-type videos providing up-to-date aspects of CFD.
• NPTEL | Chemical Engineering |Computational Fluid Dynamics: lecture-type videos providing fundamentals of CFD.
• Wikipedia | Computational Fluid Dynamics
• OpenFOAM | User Guide