Difference between Parasite Drag and VSPAERO

[Simon Boudoux]

Good afternoon,

I have a question regarding the difference between Parasite Drag and VSPAERO. Why is the Parasite Drag not used for Cd0 in the VSPAERO Module is there a reason ? And which one is more accurate for the Cd0 ? 

Have a good day,

Simon Boudoux

[Rob McDonald]

They are separate.  They do not have anything to do with one another.

They are different tools.  VSPAERO only knows about the components participating in the VSPAERO model.  The Parasite Drag tool can make all kinds of adjustments to different components and can include things not in the VSPAERO model.

The VSPAERO model does  a strip-wise model on lifting surfaces that knows about the local velocity, Reynolds and Mach numbers.  This is particularly a benefit for rotating wings.

There are changes underway to the VSPAERO parasite drag model that will be a big improvement.

The tools will still most likely stay separate.

Rob

[Simon Boudoux]

Thanks for the answer !

So if I want to extract the aerodynamic coefficient is it better to choose the Cd0 from the Parasite Drag Tool or the VSPAERO Stab Analysis ? Like in my case I am studying airships and trying to build a model based on those coefficients and I was wondering if there are some indications on which one would be better

Simon