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New Member
G Gruber
Join Date: Mar 2009
Location: Bavaria, Germany
Posts: 22
Rep Power: 17 ![]() |
Hello,
i need help for a simple example with OpenFOAM. Given: Inlet: Zylinder with Diameter 125mm (200mm long) A Inlet = D Inlet²*Pi/4 = 0,125² *3.14 / 4 = 0.0123m² Vpoint=2400l/min=0.04m³/s Fluid Oil: rho=0.9kg/dm³=900kg/m³ eta= 1 Pa s = 1 kg / (m s) Outlet: Zylinder with Diameter 200mm (200mm long) A Outlet = D Outlet²*Pi/4 = 0,2² *3.14 / 4 = 0.0314m² 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 Inlet² / 2= 900 * 3,25² / 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 m² / 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 Outlet² / 2= 900 * 1,27² / 2 = 725,805 Pa My problem is: The fact that the speed (picture tube-u0) and Pressure (picture tube-p0) 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. |
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Thread | Thread Starter | Forum | Replies | Last Post |
Density in icoFoam Densidad en icoFoam | manuel | OpenFOAM Running, Solving & CFD | 8 | September 22, 2010 04:10 |
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Need help for a simple example with icoFOAM | gruber2 | OpenFOAM Running, Solving & CFD | 3 | April 3, 2007 06:26 |