What is CFD? — Lesson 1

This course introduces Ansys Fluent for new and occasional users, covering the basics of what CFD is and how it functions. CFD is defined as a method to predict fluid flow, heat and mass transfer, chemical reactions, and related phenomena by solving fundamental physics equations.

CFD provides detailed information about flow fields, including the distribution of pressure, velocity, and temperature. It can determine forces like drag and lift, analyze multiphase systems and the distribution of phases, and provide insights into chemical reactions, combustion, and pollutant formation.

CFD is widely used in engineering for conceptual studies, product development, optimization, troubleshooting, and redesign. It significantly complements physical testing and experimentation by reducing the total effort and cost, allowing for fewer tests and providing detailed information that is often difficult to obtain through experiments alone.

Ansys CFD solvers use the finite volume method. This involves discretizing the system (domain) into a finite set of control volumes, creating a mesh. For each control volume, equations like conservation of mass, momentum, and energy are written.

The general form of these equations includes terms for unsteady behavior, convection, diffusion, and source terms. These partial differential equations are discretized into a system of algebraic equations for each control volume, where the solution for a cell depends on its neighbors. Numerical methods are then used to solve this system, yielding the CFD solution.