[siw]

Hi,

The two Momentum Source loss models (isotropic and directional) shown in the CFX Theory Guide (eqs. 1.146 and 1.149) show that the loss coefficient is multiplied by density / 2.

When comparing these equations with the Dupuit-Forchheimer equation (http://en.wikipedia.org/wiki/Darcy's...non-Darcy_flow) the loss coefficient there (Greek letter beta) is multiplied only by density.

I have dervied my loss coefficient from experimental data as like in the Dupuit-Forchheimer equation. So I just want to check if I should really be doubling this value in CFX-Pre so that CFX halves it as shown in the Theory Guide. I'm not sure why CFX uses the 1 / 2. But I've only found reference to the Dupuit-Forchheimer equation in wiki and no actual fluids textbooks.

Thanks.