Outlet
The Outlet node defines boundaries where the fluid leaves the domain. This condition uses the HLLC Riemann Solver (Ref. 1) to determine the incoming and outgoing characteristics and provide the appropriate flux.
Flow Properties
Select the set of variables to be defined in Input State — Primitive variables (the default), or Conservative variables.
For the Water depth, select User defined (the default), From domain values, or Specify total height.
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For User defined provide a value or an expression for the water depth h0. The default is 0 m.
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When From domain values is selected, the value of the water depth used to defined the external state is taken from the solution at the boundary. Note that in supercritical outlets both water depth and water flux should be taken from domain values.
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For Specify total height provide a value or an expression for the Total height of the water column H0. The default is 0 m. When using this option, the external water depth is calculated as
The variable used to define the external water flux q0 will depend on the Input state:
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For Primitive variables the velocity is provided. If User defined is select, provide a value or an expression for the components of the velocity u0. The default is 0 m /s. The outgoing water flux is then calculated as
If From domain values is selected, the value of the velocity used to defined the external state is taken from the solution at the boundary. Note that in supercritical outlets both water depth and water flux should be taken from domain values.
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For Conservative variables the water flux is required. If User defined is select, provide a value or an expression for the components of the water flux q0. The default value is 0 m2 /s. If From domain values is selected, the value of the water flux used to defined the external state is taken from the solution at the boundary. In supercritical outlets both water depth and water flux should be taken from domain values.