OpenFOAM guide/Programmer's Guide Errata

From OpenFOAMWiki

Community created Errata for the OpenFOAM Programmer's Guide:

  • Online version: OpenFOAM Programmer's Guide at SF.net
  • The local version in your OpenFOAM installation can be found by running this command:
    echo $WM_PROJECT_DIR/doc/Guides-a4/ProgrammersGuide.pdf



Notes to contributors: Please include the chapter number of the printed version to avoid confusion (the Wiki might give different chapter numbers)



1 Chapter 1: Tensor mathematics

1.1 Section 1.2: Tensors

As reported in the bug report #1068, there are a couple of references to OpenFOAM 1.x, which is likely an old reference to the original FOAM 2.x version. Feel free to compare to the old documentation at Nabla: the old Programmer's Guide, section 1.2 Tensors.

Either way, feel free to disregard the 1.x reference, since its objective is reflect that tensors as a mathematical entity, are only partially implemented in OpenFOAM.


1.2 Section 1.4: OpenFOAM tensor classes

1.2.1 Subsection 1.4.1: Algebraic tensor operations in OpenFOAM

Valid versions: OF version 16.png OF version 17.png OF Version 20.png OF Version 21.png OF Version 22.png

In Table 1.2: Algebraic tensor operations in OpenFOAM, the following entries need fixing:

Operation Description in OpenFOAM
(wrong)
Description in OpenFOAM
(correct)
Component maximum max(a) cmptMax(a)
Component minimum min(a) cmptMin(a)
Scale scale(a,b) cmptMultiply(a,b)

2 Chapter 2: Discretisation procedures

2.1 Section 2.1: Differential operators

2.1.1 Subsection 2.1.2: Divergence

Valid versions: OF version 15.png OF version 16.png OF version 17.png OF Version 20.png OF Version 21.png

(Note: Already fixed in OF Version 22.png)

The documented divergence operator for tensors is incorrect:


\nabla \bullet T = \partial_i T_{ij}=\left(
\begin{matrix}
\frac{\partial T_{11}}{\partial x_1}     + \frac{\partial T_{12}}{\partial x_1}     + \frac{\partial T_{13}}{\partial x_1}\\
\frac{\partial T_{21}}{\partial x_2}     + \frac{\partial T_{22}}{\partial x_2}     + \frac{\partial T_{23}}{\partial x_2}\\
\frac{\partial T_{31}}{\partial x_3}     + \frac{\partial T_{32}}{\partial x_3}     + \frac{\partial T_{33}}{\partial x_3}    
\end{matrix}
\right)

It should be:


\nabla \bullet T =
\left(
\begin{matrix}
\frac{\partial }{\partial x_1}, & \frac{\partial }{\partial x_2}, & \frac{\partial}{\partial x_3}
\end{matrix}
\right)
\bullet
\left(
\begin{matrix}
T_{11} &    T_{12} &    T_{13}    \\
T_{21} &    T_{22} &    T_{33}    \\
T_{31} &    T_{32} &    T_{33}    \\
\end{matrix}
\right)
=\partial_j T_{ji}=\left(
\begin{matrix}
\frac{\partial T_{11}}{\partial x_1}     + \frac{\partial T_{21}}{\partial x_2}     + \frac{\partial T_{31}}{\partial x_3}\\
\frac{\partial T_{12}}{\partial x_1}     + \frac{\partial T_{22}}{\partial x_2}     + \frac{\partial T_{33}}{\partial x_3}\\
\frac{\partial T_{13}}{\partial x_1}     + \frac{\partial T_{32}}{\partial x_2}     + \frac{\partial T_{33}}{\partial x_3}    
\end{matrix}
\right)


2.2 Section 2.4: Equation discretisation

2.2.1 Subsection 2.4.6: Gradient

Valid versions: OF version 16.png OF version 17.png OF Version 20.png OF Version 21.png OF Version 22.png

  • All references to timeScheme should be either gradSchemes or snGradSchemes [1].
  • The indication of [Check**] implies that this subsection needs to be revised.


2.2.2 Subsection 2.6.1: Physical boundary conditions

Valid versions: OF version 16.png OF version 17.png OF Version 20.png OF Version 21.png OF Version 22.png

  • The indication of [Check**] implies that this subsection needs to be revised.


3 Chapter 3: Examples of the use of OpenFOAM

4 Chapter 4: Programming techniques


5 Known forum threads on this topic

This is a unordered list of links to threads about typos and errors in the Programmer's Guide that have been found by the community: