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Ramjet Intake Simulation

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Old   October 26, 2012, 06:45
Default Ramjet Intake Simulation
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Hi all,

I am trying to simulate (Inviscid FLow) a Ramjet Intake. Please find the geometry and BC in the attached figure.

I used the following BC
  1. Inlet - Pressure Inlet
  2. Freestream - Pressure Farfield
  3. symmetry - axis
  4. wall - slip
  5. outlet - Pressure Outlet

I specified pressure at the outlet to get a normal shock in the constant area portion of the intake.

First i initialized with fully supersonic flow and specified static pressure at the outlet, but the outlet BC was not sensed, which the simulation resulted in fully supersonic flow.

So i initialized with fully subsonic flow and specified static pressure at the outlet, but the flow reversal at the outlet and the solution is not converging.

So what would be a good strategy to simulate this kind of problem in fluent.
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Old   October 27, 2012, 14:20
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you should'nt specify a far field in such close proximity to your region of interest, well that true of most Bc's. Remember at a BC your are fixing values and if this is close to large gradients then you specify one side of that field.

If you want to model a nacelle with a ramjet inside then if this were to be 3 metres long for example the far field should be a half elipse shape, nominally 60m in diameter.
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Old   October 27, 2012, 14:27
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create the free stream boundary in front and extend the outlet boundary.
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