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-   -   Need help for a simple example with icoFOAM (http://www.cfd-online.com/Forums/openfoam-solving/59755-need-help-simple-example-icofoam.html)

gruber2 April 3, 2007 04:33

Hello, i need help for a si
 
Hello,

i need help for a simple example with OpenFOAM.

Given:
Inlet: Zylinder with Diameter 125mm (200mm long)
A Inlet = D Inlet≤*Pi/4 = 0,125≤ *3.14 / 4 = 0.0123m≤
Vpoint=2400l/min=0.04m≥/s
Fluid Oil: rho=0.9kg/dm≥=900kg/m≥
eta= 1 Pa s = 1 kg / (m s)
Outlet: Zylinder with Diameter 200mm (200mm long)
A Outlet = D Outlet≤*Pi/4 = 0,2≤ *3.14 / 4 = 0.0314m≤

Necessary values for the calculation with OpenFOAM:
v Inlet=Vpoint / A Inlet= 0.04 / 0.0123 = 3.25 m/s -> inscribed in $FOAM_RUN/tutorials/icoFoam/tube/0/U
p Inlet= rho * v Inlet≤ / 2= 900 * 3,25≤ / 2 = 4753.125 Pa -> inscribed in $FOAM_RUN/tutorials/icoFoam/tube/0/p
Re = D Inlet * v Inlet * rho / eta = 0,125 * 3.25 * 900 / 1 = 365,625 <re> laminar Flow -> Solver: icoFOAM
ny = D Inlet * v Inlet / Re = 0,125 * 3.25 / 365,625 = 0.001 m≤ / s -> inscribed in $FOAM_RUN/tutorials/icoFoam/tube/constant/transportProperties
endTime 0.5; deltaT 0.005; writeInterval 20 -> inscribed in $FOAM_RUN/tutorials/icoFoam/tube/system/controlDict
div(phi,U) Gauss <>; changed in -> div(phi,U) Gauss linear; in $FOAM_RUN/tutorials/icoFoam/tube/system/fvSchemes:

Requested values:
v Outlet, p Outlet
Calculated values for Control:
v Outlet=v Inlet * A Inlet / A Outlet = 3.25 * 0.0123 / 0.0314 = 1,27 m/s
p Outlet= rho * v Outlet≤ / 2= 900 * 1,27≤ / 2 = 725,805 Pa

My problem is:
The fact that the speed and Pressure is indicated only in the Inlet at the start time and not for all other times, it is also not to be recognised with the filter glyth.


Sorry for the many postings the file-upload isn't very easy.


http://www.cfd-online.com/OpenFOAM_D...s/mime_zip.gif tube.zip
http://www.cfd-online.com/OpenFOAM_D...s/mime_txt.gif U
http://www.cfd-online.com/OpenFOAM_D...s/mime_txt.gif p
http://www.cfd-online.com/OpenFOAM_D...s/mime_txt.gif transportProperties
http://www.cfd-online.com/OpenFOAM_D...s/mime_txt.gif controlDict
http://www.cfd-online.com/OpenFOAM_D...s/mime_txt.gif fvSchemes

gruber2 April 3, 2007 05:47

Here are some pictures
 
Here are some pictures





gruber2 April 3, 2007 05:50

Sorry the size of the pictures
 
Sorry the size of the pictures is to large for the board

hjasak April 3, 2007 06:26

Sounds like you need a support
 
Sounds like you need a support contract and not just "help".

Hrv


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