10-02-2012, 02:24 PM
Computational Fluid Dynamics
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What is CFD?
Computational Fluid Dynamics (CFD) is the science of predicting fluid flow, heat transfer, mass transfer, chemical reactions, and related phenomena by solving the mathematical equations which govern these processes using a numerical process.
The result of CFD analyses is relevant engineering data used in:
conceptual studies of new designs
detailed product development
troubleshooting
redesign
CFD analysis complements testing and experimentation.
Reduces the total effort required in the laboratory.
CFD - How It Works
Analysis begins with a mathematical model of a physical problem.
Conservation of matter, momentum, and energy must be satisfied throughout the region of interest.
Fluid properties are modeled empirically.
Simplifying assumptions are made in order to make the problem tractable (e.g., steady-state, incompressible, inviscid, two-dimensional).
Provide appropriate initial and/or boundary conditions for the problem.
Mesh Generation
Geometry created or imported into preprocessor for meshing.
Mesh is generated for the fluid region (and/or solid region for conduction).
A fine structured mesh is placed around cylinders to help resolve boundary layer flow.
Unstructured mesh is used for remaining fluid areas.
Identify interfaces to which boundary conditions will be applied.
cylindrical walls
inlet and outlets
symmetry and periodic faces