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Mehdi BEN ELHADJ May 1, 2001 10:17

A bout velocity components
In the finite volume method the velocity components are calculated on the cell faces. but we remark that:

1- The speed vectors are ploted in grid centers (in photon)!

2- In the PHI (or Result) file we have the values of velocity components in the cell center!

is it an interpolation ? what kind ?

David Glynn June 18, 2001 09:24

Re: A bout velocity components
In PHI or RESULT the values of U1, V1, W1 are staggered and pertain at centres of cell faces.

In PHOTON they are averaged to the cell centre by a straightforward arithmetic mean. This averaging in PHOTON can be switched off by SET VEC AV OFF. Strictly speaking this is a preferable option when you are using BFCs. When a staggered velocity resolute is not available (e.g. on a boundary), PHOTON makes an intelligent assumption about it. (NB The VR Viewer assumes zero on a boundary, although I gather this will improve in 3.4).

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