1.1 Solution overview

Let us imagine calculating fluid flow along a pipe with CFD. To perform the calculation first requires a description of the problem by:

  • the domain occupied by the fluid, i.e. the internal region of the pipe;
  • equations that represent the fluid behaviour, in terms of properties such as pressure eqn and velocity eqn;
  • conditions at the boundary of the fluid domain and initially within the domain for the fluid properties.

This description is represented in CFD by the following:

  • a computational mesh for the fluid;
  • “discrete” equations and algorithms to calculate eqn and eqn;
  • boundary and initial conditions for eqn and eqn.

Chapter 2 introduces the governing equations and basic models for fluid motion, forces and heat. Turbulence, which commonly occurs in many flows, is introduced in Chapter 6 and its standard modelling is described in Chapter 7 .

The finite volume method is presented in Chapter 3 to express equations in discrete form using its geometric representation of a computational mesh. The algorithms used to solve the matrix equations and to couple sets of equations are given in Chapter 5 .

Chapter 4 describes boundary conditions first from a numerical perspective, i.e. how they modify the matrix equations to influence the solution. It then covers a range of conditions that represent the behaviour at boundaries in many problems.

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Notes on CFD: General Principles - 1.1 Solution overview