Computational Fluid Dynamics (CFD): Introduction

1. Course Overview

• Focus on numerical methods and equation discretization in CFD
• Bridge knowledge gap for ANSYS Fluent users
• Designed for both working professionals and newcomers
• Emphasis on understanding solver mechanics rather than coding

2. What is CFD?

• Numerical approach to solve fluid dynamics governing equations
• Transforms nonlinear PDEs into solvable linear algebraic equations
• Uses discretization methods, primarily finite volume method in ANSYS Fluent
• Essential tool for simulating complex fluid flow phenomena

3. Applications

• Aerospace: Aircraft and vehicle aerodynamics
• Marine: Ship hydrodynamics, offshore structures
• Power Generation: Combustion analysis
• Industrial: Chemical processes, HVAC systems
• Environmental: Pollution dispersion
• Biomedical: Blood flow analysis

4. CFD Solution Process a) Problem Understanding

• Analyze real flow behavior
• Identify key physical phenomena

b) Modeling Steps

• Physical model development
• Mathematical formulation
• Numerical solution through discretization
• Results analysis and validation

5. Numerical Methods a) Finite Difference Method (FDM)

• Uses structured grids
• Simple implementation
• Limited to basic geometries

b) Finite Volume Method (FVM)

• Handles complex geometries
• Ensures conservation laws
• Used in ANSYS Fluent

c) Finite Element Method (FEM)

• Suitable for complex geometries
• Common in structural mechanics
• More computationally intensive

6. Mathematical Foundation

• PDE classifications (First/Second order, Linear/Non-linear)
• Elliptic, Parabolic, and Hyperbolic equations
• Taylor series for discretization
• Conservation equations and transport phenomena

7. Error Sources in CFD

• Round-off errors
• Truncation errors
• Modeling errors
• Grid-dependent accuracy