CFD Online Discussion Forums

OpenFOAM Installation for Multiple Users

Posted March 9, 2013 at 08:26 by Hisham (Notes for OpenFOAM!)
Updated March 10, 2013 at 10:47 by Hisham

If OpenFOAM was installed on a single user account using the OpenCFD binaries then for another user to have access to it is very simple. All one needs to do is to add an alias of the installation in the new user's .bashrc file

Code:

OFver='source /opt/openfoamver/etc/bashrc'

If, on the other hand, OpenFOAM (or OpenFOAM-ext) was compiled on a user account (say the user name is MrX) and a new user (MrY) wants to use the same installation, then:

1. MrX must make sure...

Hisham

Senior Member

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Floating Point Math in Bash

Posted March 6, 2013 at 13:35 by Hisham (Notes for OpenFOAM!)

Tags bash, floating point numbers

This post is copied from: http://www.linuxjournal.com/content/...oint-math-bash
Floating Point Math in Bash, By Mitch Frazier

To use floating point arithmetic in Bash one can source this script (i.e. source floatSupport.sh). The floatSupport.sh is:

Code:

#!/bin/bash 
# 
# Floating point number functions. 

##################################################################### 
# Default scale used by float functions.

...

Hisham

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PISO's strange behavior at different meshes :(

Posted February 25, 2013 at 06:19 by skeptik (CFD notes)

1. mesh quad+tri+3D extruded. at 17 grad most flow around airfoil is laminar

Name: piso_17_hybrid.jpg
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Size: 16.3 KB

2. mesh only tri+3D extruded. at 15 grad flow behind foil is completely turbulent

Name: piso15_wake.jpg
Views: 382
Size: 20.6 KB

so this pictures shows that we cannot get proper results for Cx, Cy due to bad prediction of the flow detachment.

try to find a solution, may be OF 2.1 will show better results

skeptik

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Bubbly flow boundary conditions

Posted February 20, 2013 at 06:58 by beauty

meeting the same problem

Quote:

Originally Posted by Vivek
;99722

Hey Danny,

It is very simple but not straight forward. In many cases you would seen people model the top gas-liquid surface as outlet using two-fluid model. But, I hope that you would agree with me that two-fluid model is not expected to predict the gas-liquid surface. Ypu can model the top gas-liquid interface as follows:

1. Set top surface as inlet. Set all componet of liquid velocity to zero. Set vertical gas velocity to terminal rise

...

beauty

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Good news about airfoil and OpenFoam

Posted February 20, 2013 at 02:42 by skeptik (CFD notes)

So, at the end of the testing OpenFOAM/simpleFoam, i get:

NACA23012
U=21.3, Re=0.44e6,

LowRe case, LaunderSharmaKE:
1. OF 1.7 cannot solve the case with kEpsilon on hex+tetra 2D mesh. It just crashes.

2. There are a lots of details when you use LowRe LSkEps model, you need lots of iteration, lots of interpolation data to provide better accuracy.

3. People invented k-omega for different flows near the walls. And better one - kOmega...

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