Aerodynamics.Supersonic_Zero() method

[Дмитрий Тарабащук]

Dear Emilio,

I have a few questions:

1) Can we trust Supersonic_Zero() method? I changed diameter/length of fuselage and almost all parameters related to fuselage didn't make change in drag coefficient except from effective diameter of fuselage.

2) For some vehicle Supersonic_Zero() showed 2 -3 times bigger drag than CFD. Can this problem occur because the geometry was imported from VSP, not created manually in SUAVE?

3)Could you explain the effectiveness of this low fidelity method?  What error of results compare to CFD analysis should be satisfactory? 10 -20% error?

Thank you for your help and work!

kind regards,

Dmitrii

[Emilio]

Hi Dmitrii,

1) Depends on the source of drag you're looking for. But yes, length and effective diameter (and fineness) are the key knobs to use. Most of this is sears haack style drag buildups.

2) Is your CFD viscous? Does your CFD account for excrescence drag sources? SUAVE will always have larger drag than anything but maybe LES CFD simulations because of the complete markup.

3) Take a look at this recent paper. It's much closer than 10-20%... let me know if you have trouble accessing it.

-Emilio