Manifold boundary conditions

Altair Forum User

Hello Sir,

 

I am modelling a manifold which looks like in the attached picture. In the inlet I can give my flow rate as boundary condition but the branch(one outlet) needs to be modelled in such a way that it exactly receives 1 lit/min and that flow will join after my restrictor. How should I do that as the outlet boundary condition in acusolve is relative pressure.

 

So here in my case I have two inlets and two outlets. If you can give me a hint to proceed it would be a great help.

 

Thank you

Prithvi

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ydigit

It is possible to do such setup with mass flux. However that should be easy to convert volume rate to mass flow rate.

 

Activate the Surface Integrated BC. So you would in essence specify two BC for outlet2.

 

Input file would look similar to below:

 

SIMPLE_BOUNDARY_CONDITION( 'outlet2' ) {
    surfaces                            = Read( 'MESH.DIR/valve.default.tet4.outlet2.tri3.ebc' )
    shape                               = three_node_triangle
    element_set                         = 'default'
    type                                = outflow
    active_type                         = all
    precedence                          = 1
    pressure                            = 0.0           # N/m2
    pressure_loss_factor                = 0.0
    hydrostatic_pressure                = off
    non_reflecting_factor               = 0.0
}

# +----------------------------------------------------------------------+
# | Integrated Boundary Condition                                        |
# +----------------------------------------------------------------------+

SURFACE_INTEGRATED_CONDITION( 'outlet2 mass_flux' ) {
    surfaces                            = Read( 'MESH.DIR/valve.default.tet4.outlet2.tri3.ebc' )
    shape                               = three_node_triangle
    element_set                         = 'default'
    variable                            = 'mass_flux'
    type                                = constant
    constant_value                      = 0.1           # kg/sec
}