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The parabolic option of PHOENICS

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An early example: a buoyant smoke plume in a tunnel

The turbulent Bunsen burner

The plane turbulent mixing layer, with a multi-fluid turbulence model

More recent compressible-flow developments are described below.

  1. Axi-symmetric jet
  2. Square-sectioned jet
  3. Plane convergent duct

The axi-symmetrical sonic jet in near-stagnant surroundings

PHOENICS has been used for the simulation of the spread of a laminar jet of compressible fluid emerging from a circular orifice into a large reservoir of the same fluid. The flow is axi-symmetrical.

Because the flow is partly sonic and partly subsonic, the PIL variable IPARAB has to be set equal to 5 in the Q1 file; and STORE(MACZ) should appear, also, in order that the appropriate testing for Mach Number can be carried out.

The typical succession of higher- and lower-pressure regions is clearly seen in the following pictures, in which the flow is from right to left.

* Mach number contours * pressure contours * axial-velocity contours * velocity vectors


The three-dimensional sonic jet in near-stagnant surroundings

PHOENICS has also been used for the simulation of the spread of a laminar jet of compressible fluid emerging from a square orifice into a large reservoir of the same fluid.

The flow is three-dimensional. The IPARAB and MACZ settings are as before.

The typical succession of higher- and lower-pressure regions is clearly seen in the following pictures.

* Mach number contours * pressure contours * axial-velocity contours * velocity vectors


Supersonic flow in a plane converging duct

When the flow is wholly supersonic, IPARAB may be set to 4 in the Q1 file; and STORE(MACZ) is not needed.

The following pictures relate to such a flow. The gas enters from the left, in a direction parallel to the lower wall.

A shock wave starts from the upper wall, in order to change the flow direction to accord with the inclination of that wall. This wave crosses the duct and is then reflected from the lower wall.

* Mach number contours * pressure contours * density contours * velocity vectors