Node84 - CFD SUPPORT

Previous: Postprocessing Up: Postprocessing Next: paraFoam

This is an automatically generated documentation by LaTeX2HTML utility. In case of any issue, please, contact us at info@cfdsupport.com.

Data conversion

For postprocessing OpenFOAM data can be converted to other format using some of following applications:

        foamToEnsight
        foamToEnsightParts
        foamToGMV
        foamToStarMesh
        foamToSurface
        foamToTetDualMesh
        foamToVTK
        foamDataToFluent
        foamMeshToFluent

OpenFOAM Training by CFD Support, CFD SUPPORT, info@cfdsupport.com +420 212 243 883 © CFD support, s.r.o., Sokolovská 270/201, 190 00 Praha 9, Czech Republic

Next: Model setting without an Up: Alternative formulation Previous: Alternative formulation Contents Index

Conclusion

We have seen there are two basic approaches to water turbine calculations.

With $\color{white} \vec{g}$ in the momentum equation
1. physical setting
2. model setting
Without explicit $\color{white} \vec{g}$ in the momentum equation

Following table shows possible boundary conditions for the pressure variable

Table: Boundary conditions

pressure
setting		inlet			outlet
$\color{white} \vec{g}$ , physical	hTP	=	$\color{white} \varrho g h_{In}$	fMV	=	$\color{white} \varrho g h_{Out}$
$\color{white} \vec{g}$ , model	hTP	=	$\color{white} \varrho g (h - h_{IO})$	fMV	=	$\color{white} 0$
$\color{white} \not{\! \vec{g}}$	hTP	=	$\color{white} \varrho g h$	fMV	=	$\color{white} 0$

We note that hTP stands for hydrostaticTotalPressure boundary condition and values listed in the Table

for this type represent values of hydrostatic pressure in the centre of mass of the inlet surface. Whereas fMV stands for fixedMeanValue boundary condition and values listed in the Table

for this type represent values of static pressure in the centre of mass of the outlet surface. We add that pressureInletVelocity boundary condition is prescribed for the inlet velocity field for all of the above settings, where the velocity magnitude is computed from the difference between total and static pressure and its direction is taken as a local normal to the inlet surface (usually planar). Also zeroGradient boundary condition is prescribed for the outlet surface for all of the above settings.

Next: Model setting without an Up: Alternative formulation Previous: Alternative formulation Contents Index

Previous: greenDyMSolver – transient, cavitation Up: TCFD Solvers Next: Incompressible Mathematical Model
_{This is an automatically generated documentation by LaTeX2HTML utility. In case of any issue, please, contact us at info@cfdsupport.com.}

Compressible Mathematical Model

The computational model solves following system of equations:

Mass conservation
Momentum conservation
Energy conservation and , two options
where: Einstein summation is used, $\partial$ is partial derivative, is i-th Cartesian coordinate, $\rho$ is density, is i-th velocity vector component, is time, is static pressure, $\tau$ shear stress tensor, $\delta_{ij}$ is Kronecker delta, is total specific energy, $\mu$ is dynamic viscosity, $S_{ij}$ is rate-of-deformation tensor, is static temperature, is Prandtl number, specific gas constant, specific heat capacity (at constant pressure), specific heat capacity (at constant volume), i-th heat flux component (Fourier law), $\lambda$ heat conductivity coefficient.
The whole system is closed with boundary conditions.