M I X T U R E B O U N D A R Y C O N D I T I O N

Select a Mixture boundary condition for the inlet—Velocity, Pressure, no viscous stress, or No viscous stress.

•If Velocity (SI unit: m/s) is selected, enter the components in the u0 fields to specify that the velocity at the boundary is equal to a given velocity vector u = u0 .

•If Pressure, no viscous stress is selected, enter the pressure p0 (SI unit: Pa) at the boundary to set the pressure to p0 and also make the viscous stress zero at the boundary:

p = p0 , + T u + uT n = 0

•If No viscous stress is selected, this boundary condition sets the viscous stress to zero at the boundary:

+ T ul + ulT n = 0

D I S P E R S E D P H A S E B O U N D A R Y C O N D I T I O N

See Inlet for the settings and Dispersed Phase Boundary Conditions

Equations for more information about the options.

Note

Symmetry

The Symmetry feature adds a boundary conditions that describe symmetry boundaries in a fluid-flow simulation. The boundary condition for symmetry boundaries prescribes no penetration and vanishing total flux:

u n = 0, t cd 1 – cd uslipuslip + Gm n = 0

B O U N D A R Y S E L E C T I O N

From the Selection list, choose the boundaries that are symmetry boundaries.

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A boundary condition for 2D axial symmetry is not required. For the symmetry axis at r 0, the program automatically provides a condition

that prescribes ur 0 and vanishing stresses in the z direction and adds an

2D Axi Axial Symmetry feature to the model that is valid on the axial symmetry boundaries only.

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