Outlet
This condition provides the fluxes to describe the flow conditions at an outlet. The applied conditions are controlled by the Flow Condition.
This condition uses the Osher–Solomon Riemann Solver (Ref. 4) to determine the incoming and outgoing characteristics, and provide the appropriate flux.
Flow Condition
Select a Flow condition — Subsonic (the default) or Supersonic.
•
For Subsonic, a subsonic (Ma < 1) outlet is specified. The imposed flux computes the density and velocity from inside the domain, and uses the pressure specified in Flow Properties.
•
For Supersonic the outlet flow is assumed to be supersonic (Ma > 1). All the characteristics are assumed to be leaving the domain, and no variable needs to be specified.
In transonic flows (0.8 < Ma < 1.2) or in cases where the flow may range from subsonic to supersonic, it is safer to use the Subsonic condition and let the characteristics based method determine the values used when computing the outlet flux.
Flow Properties
This section is available when Subsonic is selected. Enter a value or expression for the Static pressure p0,stat (SI unit: Pa).