Hi,
I am using FlightStream v26.0 to estimate the drag of a standalone fuselage based on a scaled-down NASA RAVEN VSP geometry. With the current setup, it appears that FlightStream may be underpredicting the drag for this geometry.
The reference area is the fuselage frontal area. The total drag coefficient I obtain is approximately:
CD≈0.073
This appears low to me when referenced to frontal area. For comparison, I would expect a higher value based on typical drag coefficients of streamlined bodies, bullets, or even airfoil-like shapes referenced to frontal area.
The main solver settings are:
- Steady solver, subsonic model
- Viscous coupling enabled
- Flow separation enabled
- Base region selected
- Surface roughness height: 6350 nm, although this does not significantly affect the solution compared to 0 nm
The case is run at:
- Angle of attack: 0 deg, also tested at 3 deg with similar results
- Sideslip angle: 0 deg
- Freestream velocity: 30 m/s
Could you please provide input on whether this drag level is expected for this setup? Also, are there any recommended changes to the solver settings, viscous/separation options, or mesh setup that I should use to obtain a more realistic standalone fuselage drag prediction?
I have attached the .fsm file and a few screenshots for reference.
Thank you.
