•The molar concentration (SI unit: mol/m3) c c0

•The number density, which describes the number of particles per volume (SI unit: 1/m3): n n0

A concentration quantity other than the mass fractions can only be used when all species are defined, as in the Inflow condition. The other quantities are composition dependent and therefore unambiguous only when all species are defined. For this reason the Mass Fraction feature, which allows some species to use a different boundary condition, only includes an input for the mass fractions.

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

From the Selection list, choose the boundaries to apply an inflow boundary condition.

P A I R S E L E C T I O N

If Inflow is selected from the Pairs menu, choose the pair to define. An identity pair has to be created first. Ctrl-click to deselect.

I N F L O W

Select the type of input from the Mixture specification list and then enter the value or expression in the fields for each species except the one computed from the mass constraint. Select:

•Mass fraction (the default) to enter mass fractions ( 0, 1, for example)

•Mole fraction to enter mole fractions (x0, 1, for example)

•Molar concentration to enter molar concentrations (c0, 1, for example)

•Number density to enter number densities (n0, 1, for example)

No Flux

The No Flux node, which is the default boundary condition, represents boundaries where no mass flows in or out; that is, the total flux is zero:

n iu + ji = 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 to apply a no-flux boundary condition.

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