[piyo]

Hello everybody,

When I read section 9.3 Swirling and Rotating Flows in the user guide document (version 12), I am totally confused about the equation of Swirl Number and its physical meaning.

The statement in the guide is shown in the attachment.

I think the radial velocity vector v should be replaced by the axial velocity vector u, because it indicates the ratio:
axial flux of angular momentum
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axial flux of axial momentum

I've searched on the Internet, and some websites give the equation in terms of axial velocity, though the definition of Swirl Number on these websites can be different from FLUENT.

If the vector v is used, I think it will be radial flux rather than axial flux.

Can anyone give me some suggestions or point out where I get wrong?


Thanks.
Piyo

[piyo]

Probably, v should be regarded as velocity vector, and A is a flat area.. Don't know whether this thinking is sensible or not...