Difference between revisions of "OpenFOAM guide/Programmer's Guide Errata"

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(→‎Known threads on this topic: found that the bug indicated on the first thread has already been fixed)
(revised page and updated a few links)
 
(4 intermediate revisions by the same user not shown)
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Community created ''Errata'' for the [http://foam.sourceforge.net/docs/Guides-a4/ProgrammersGuide.pdf OpenFOAM ''Programmer's Guide''].
+
Community created ''Errata'' for the OpenFOAM ''Programmer's Guide'':
 +
* Online version: [https://sourceforge.net/projects/openfoamplus/files/v1606+/ProgrammersGuide-v1606.pdf OpenFOAM ''Programmer's Guide'' at SF.net]
 +
* The local version in your installation can be found by running one of the respective commands:
 +
** On OpenFOAM 3.0 and older, as well as foam-extend and all OpenFOAM+ versions: <bash>echo $WM_PROJECT_DIR/doc/Guides-a4/ProgrammersGuide.pdf</bash>
 +
** As of OpenFOAM 4, there is no Programmer's Guide. This is now maintained by the [http://openfoam.com OpenFOAM+ project].
  
−
Notes to contributors: Please include the chapter number of the printed version to avoid confusion (the Wiki might give different chapter numbers)  
+
<br>
 +
<hr>
 +
'''Notes to contributors:''' Please include the chapter number of the printed version to avoid confusion (the Wiki might give different chapter numbers)  
 +
<hr>
 +
<br>
  
 
= Chapter 1: Tensor mathematics =
 
= Chapter 1: Tensor mathematics =
 +
 +
 +
== Section 1.2: Tensors ==
 +
 +
As reported in the [http://bugs.openfoam.org/view.php?id=1068 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 [http://www.foamcfd.org/Nabla/guides/ProgrammersGuidese2.html#x5-40001.2 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.
  
  
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| Scale || scale(a,b) || cmptMultiply(a,b)
 
| Scale || scale(a,b) || cmptMultiply(a,b)
 
|}
 
|}
−
 
  
 
= Chapter 2: Discretisation procedures =
 
= Chapter 2: Discretisation procedures =
 +
 +
== Section 2.1: Differential operators ==
 +
 +
=== Subsection 2.1.2: Divergence ===
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{{versionInfo}}{{Version1.5}}{{Version1.6}}{{Version1.7}}{{Version2.0}}{{Version2.1}}
 +
 +
('''Note''': Already fixed in {{Version2.2}})
 +
 +
The documented divergence operator for tensors is incorrect:
 +
 +
<math>
 +
\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)
 +
</math>
 +
 +
It should be:
 +
 +
<math>
 +
\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)
 +
</math>
 +
  
 
== Section 2.4: Equation discretisation ==
 
== Section 2.4: Equation discretisation ==
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<br>
 
<br>
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= Known threads on this topic =
+
= 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:
 
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:
  
 
* [http://www.cfd-online.com/Forums/openfoam-bugs/104867-bug-programmers-guide-divergence-tensor-field.html Bug in the programmer's guide: divergence of a tensor field]
 
* [http://www.cfd-online.com/Forums/openfoam-bugs/104867-bug-programmers-guide-divergence-tensor-field.html Bug in the programmer's guide: divergence of a tensor field]
−
** Only affects {{version1.4.1}}
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** Documented in [[#Subsection 2.1.2: Divergence|Subsection 2.1.2: Divergence]], but keep in mind that this has already been fixed.
 
* [http://www.cfd-online.com/Forums/openfoam-bugs/82225-programmers-guide-p-40-a.html In Programmer's Guide p. 40]
 
* [http://www.cfd-online.com/Forums/openfoam-bugs/82225-programmers-guide-p-40-a.html In Programmer's Guide p. 40]
 
** The issues in post #1 are at [[#Subsection 2.4.6: Gradient|Subsection 2.4.6: Gradient]] and [[#Subsection 2.6.1: Physical boundary conditions|Subsection 2.6.1: Physical boundary conditions]]
 
** The issues in post #1 are at [[#Subsection 2.4.6: Gradient|Subsection 2.4.6: Gradient]] and [[#Subsection 2.6.1: Physical boundary conditions|Subsection 2.6.1: Physical boundary conditions]]
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** The issues indicated in post #1 are already here in the wiki in the subsection [[#Subsection 1.4.1 Algebraic tensor operations in OpenFOAM|Subsection 1.4.1 Algebraic tensor operations in OpenFOAM]].
 
** The issues indicated in post #1 are already here in the wiki in the subsection [[#Subsection 1.4.1 Algebraic tensor operations in OpenFOAM|Subsection 1.4.1 Algebraic tensor operations in OpenFOAM]].
 
* [http://www.cfd-online.com/Forums/openfoam-bugs/62533-error-documentation.html Error in documentation]
 
* [http://www.cfd-online.com/Forums/openfoam-bugs/62533-error-documentation.html Error in documentation]
 +
** Only affects {{version1.4.1}}
  
 
[[Category:OpenFOAM guide]]
 
[[Category:OpenFOAM guide]]

Latest revision as of 13:38, 20 August 2016

Community created Errata for the OpenFOAM Programmer's Guide:

  • Online version: OpenFOAM Programmer's Guide at SF.net
  • The local version in your installation can be found by running one of the respective commands:
    • On OpenFOAM 3.0 and older, as well as foam-extend and all OpenFOAM+ versions: 
      echo $WM_PROJECT_DIR/doc/Guides-a4/ProgrammersGuide.pdf
    • As of OpenFOAM 4, there is no Programmer's Guide. This is now maintained by the OpenFOAM+ project.


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:

Retrieved from "https://openfoamwiki.net/index.php?title=OpenFOAM_guide/Programmer%27s_Guide_Errata&oldid=18327"
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