[RON1991]

Hi everybody,

I have a doubt about the "reference values" in FLUENT.

I want to simulate a H-rotor DARRIEUS, with these characteristics :
. H=0.4m
. R=0.3m
. S=2*R*H=0.24m²
What are the values for "Depth" and for "Length" in FLUENT ??
I thought that "Depth"=H, and "Length"=R...
BUT I've seen that if I double the value of "Depth" in the reference values, the moment coefficient (Cm) is also double; however, Cm=C/(0.5*ro*S*R*Uinf²), isn't it ? So with the same values of "length" and "Area", Cm would be the same, no ?

Thank you very much for your explanations !

[LuckyTran]

The depth property is only for 2D simulations for scaling of the cell volumes in the "depth" direction.

In 3D you would be correct (although there would be no depth reference). However, in 2D you cannot increase the depth while keeping the physical area constant (since the force is the product of the pressure and physical area). That is, when you double the depth you double the area over which the pressures act and hence the force is doubled.

[RON1991]

Thank you very much for your answer LuckyTran