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## Boundary and Initial Conditions of fan-noHousing-compressible

Following table shows recommended model of boundary conditions for computed variables:

The shortcuts from the table above have following meaning:

- pTot –
*totalPressure*prescribes fixed total pressure - pDIV –
*pressureDirectedInletVelocity*prescribes velocity angles at the inlet, but the velocity magnitude is computed from total pressure – static pressure difference - oV –
*outletVent*prescribes special static pressure to imitate valve - fRV –
*flowRateVelocity*prescribes fixed flow rate - hTP –
*hydrostaticTotalPressure*sets the total pressure at a patch including linear distribution of hydrostatic pressure in the gravity direction with respect to a reference value*pInletCenter*(e.g. ) in the center of a patch. - tIKEI –
*turbulentIntensityKineticEnergyInlet*,*intensity*= 0.05, corresponds to turbulence intensity 5% - fV –
*fixedValue*, e.g. velocity at the wall (0 0 0), or omega at inlet - fMV –
*fixedMeanValue*, is the same as fixed value, e.g. for pressure, but certain freedom is allowed to keep the variable average equal to*meanValue* - zG –
*zeroGradient*, the flux is zero in direction perpendicular to the surface - kWF –
*kqRWallFunction*is a standard wall function for k for incompressible flow - oWF –
*omegaWallFunction*is a standard wall function for omega for incompressible flow - mI –
*mixingInterface*, averaged quantity is mapped from the neighbour patch - iO –
*inletOutlet*is by default*zeroGradient*, but changes to*fixedValue*when velocity vector direction points inside the computational domain (backward flow)

See also Chapter (), where the boundary conditions are described.

NOTE: In this particular tutorial case the surface model is simplified and the spiral is closed at the end of the wheel (no full housing is considered). The closing wall might have a special boundary condition for velocity. Either standard fixed wall (fixedValue), or *rotatingWallVelocity*.

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