Inlet
This condition provides the fluxes to describe the flow conditions at an inlet. 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 — Supersonic (the default) or Subsonic.
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For Subsonic, a subsonic (Ma < 1) inlet is specified. The imposed flux uses the imposed density and velocity, and computes the pressure from the interior of the domain.
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For Supersonic the inlet flow is assumed to be supersonic (Ma > 1). A full set of variables must be provided in Flow Properties. The numerical flux can determine which characteristics are entering and leaving the domain, and can use values from inside the domain when the condition requires it.
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 Supersonic condition and let the characteristics based method determine the values used when computing the inlet flux.
Flow Properties
Specify the flow properties at the inlet. If the inlet is Subsonic, enter values or expressions for the Static density ρ0,stat (SI unit: Pa) and Velocity u0 (SI unit: m/s).
In Supersonic inlets, the inlet can be specified in terms of primitive variables, conservative variables, or a combination of static or total primitive variables and Mach number. Select an Input state — Primitive variables (the default), Conservative variables, Static state, or Total state.
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For Primitive variables enter values or expressions for the Static density ρ0,stat (SI unit: kg/m3), Velocity u0 (SI unit: m/s), and Static pressure p0,stat (SI unit: Pa).
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For Conservative variables enter values or expressions for the Static density ρ0,stat (SI unit: kg/m3), Momentum m0 (SI unit: kg/(m2 s), and Total energy etot (SI unit: J/m3).
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For Static state enter values or expressions for the Static pressure p0,stat (SI unit: Pa), Static temperature T0,stat (SI unit: K), and Mach number Ma0 (dimensionless).
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For Total state enter values or expressions for the Total pressure p0,tot (SI unit: Pa) and Total temperature T0,tot (SI unit: K), and Mach number Ma0 (dimensionless).
The relationships between the static and total states are:
(6-3)
Select a Flow direction — Normal inflow (the default) or User defined to specify an arbitrary flow direction. Then enter the components of the direction normal nM (dimensionless).