DIASP
Meeting #6
Turin 4-5 February 2003
“The Use of VSAero CFD Tool in the UAV
Aerodynamic Project “
Alberto PORTO – Massimiliano FONTANA
Porto Ricerca FDS
Giulio ROMEO - Enrico CESTINO – Giacomo FRULLA
Politecnico di Torino, Dept. of Aerospace Eng.
DIASP
Porto Ricerca S.n.c.
Monza, (Milano)
Italy
• Providers of CFD Software
• Engineering Research
• Consulting Services
DIASP
CAD
Flow Analysis Components
GRID
GENERATION
AMIGRID
SPIN
GRIDALL
FLOW
SOLUTION
VSAERO
USAERO
MGAERO
NSAERO
Property of Dept. Of Aerospace Eng., Politecnico di Torino. All rights reserved
POST PROCESSING
OMNIPLOT
OMNI3D
TECPLOT
DIASP
VSAERO
¾ Subsonic, Quasi-Steady Flow
¾ Integral Panel/Boundary Layer Method
¾ Complex Geometries
9 Thick and Vortex Lattice Surfaces
¾ Wake Modeling
¾ Performance
¾ Stability and Control
Boeing 727-200
• Lateral Symmetry
• 4100 Body Panels
• 3900 Wake Panels
• 1 Wake Iteration
• 3 Viscous Iterations
• CPU Requirement:
ŠSGI 4D/35 (R3000) 1.5
Hours
ŠSGI (R10000) 5 Minutes
Boeing 727-200
DIASP
Akron - Airship
the modified Stratford criteria
of Mendenhall35 have been
added to VSAERO to find the
cross flow separation line.
DIASP
Akron - Airship
Racing car
LANGLEY FULL SCALE WIND
TUNNEL LFST
CFD analysis during the designee
process research
Wing tunnel drag coefficient: 0.372
CFD drag coefficient prediction: 0.358
Drag coefficient error: 4%
VICTORY Challenge
Americas Cup Sailboat
CFD analysis during the designed process research
1.02
AC-b as e
AC-2 Vs aero
AC-2 Tank tes t
1.01
1
0.99
0.98
0.97
0.96
0.95
0.94
0
1
2
3
4
5
Speed
6
7
8
9
10
Percentage
difference
in drag on
two
different
Americas
Cup yachts
calculated
with
VSAERO
and tested
in a towing
tank.
CFD Wave height calculation
6
5
4
Dif. Vs a e ro
3
2
1
0
0
0.5
1
1.5
-1
-2
Speed
2
2.5
3
% error
in drag
vs. speed
for the
an
upwind
3.5
case
Heliplat®
Solar-powered UAV
ASI & EC (Helinet) projects
Span:73m; TOGM:750kg; Mass PL:100kg
Power PL:1kW; Req. Power=6 kW;
TAS=71 km/h; Altitude: 17km;
Endurance: 6 months
Effic. s.c.:20%; Effic. f.c.+elect:60%
® Trademark of Dept. of Aerospace
Engineering of Politecnico di Torino
Property of Dept. Of Aerospace Eng., Politecnico di Torino. All rights reserved
Heliplat®
CASA Space- EADS
® Trademark of Dept. of Aerospace
Engineering of Politecnico di Torino
POLITO /
ARCHEMIDE
Property of Dept. Of Aerospace Eng., Politecnico di Torino. All rights reserved
Heliplat®
® Trademark of Dept. of Aerospace
Engineering of Politecnico di Torino
Property of Dept. Of Aerospace Eng., Politecnico di Torino. All rights reserved
Heliplat®
DIASP
Preliminary wing - optimization
In the preliminary wing analysis we
have tested with VSAERO three
airfoils on wing solo configuration
MH32, E216, FX63137
E216 show a better
compromise between the
airfoil Drag and the
induced wing Drag
® Trademark of Dept. of Aerospace
Engineering of Politecnico di Torino
DIASP
Heliplat®
Wing airfoil geometry–2D XFOIL optimization
thickness effect
camber effect
combined effect
® Trademark of Dept. of Aerospace
Engineering of Politecnico di Torino
Heliplat®
By Using XFOIL, the optimal airfoil HPF118 has been designed instead of
E216.The good performances of HPF118 are also demonstrated by
experimental investigation in the Laminar Wind Tunnel in Stuttgart.
Property of Dept. Of Aerospace Eng., Politecnico di Torino. All rights reserved
Heliplat®
The optimization of wing planform have the intention to minimize induced
drag. Indeed it was found that some wing planforms increase the friction
drag more than the induced drag reduction. Each wing have constant span
and equal surface, i.e. AR=cost.
Aerodynamics Efficiency
50
48
46
44
E
42
40
Rectangular Wing- FX63137
38
PIANTA0- FX 63137
36
PIANTA0- E216
PIANTA0- HPF118
34
PIANTA8- HPF118
32
PIANTA8 twisted- HPF118 family
30
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
CL
Property of Dept. Of Aerospace Eng., Politecnico di Torino. All rights reserved
DIASP
Why we have choose to use Vsaero panel
methods technology?
• Contain the right physics
• Handle complex & arbitrary geometry
• Resolve all important physical & geometric length scale
• Reliably accurate numerics
• Timely
• Properly validated
• Can be run many, many times
Heliplat®
DIASP
CP Cf visualization all over the Airplane
Property of Dept. Of Aerospace Eng., Politecnico di Torino. All rights reserved
Heliplat®
Accurate pressure distribution on Heliplat complete configuration
CP Station cut
CP buttline cut
Property of Dept. Of Aerospace Eng., Politecnico di Torino. All rights reserved
Heliplat®
The geometry panels are divided into several groups in order to identify
the single part contribution to the total DRAG and LIFT coefficient
® Trademark of Dept. of Aerospace
Engineering of Politecnico di Torino
Property of Dept. Of Aerospace Eng., Politecnico di Torino. All rights reserved
Heliplat®
Propeller - analysis
Skin friction coefficient
Property of Dept. Of Aerospace Eng., Politecnico di Torino. All rights reserved
Heliplat®
DIASP
Derivatives study
Aileron
Stabilizer
Rudder
Static derivatives Cm_δe ; CL_δe ; CFy_δa ; Cl_δa ; Cn_δa ; CFy_δr ; Cl_δr ; Cn_δr
Property of Dept. Of Aerospace Eng., Politecnico di Torino. All rights reserved
Heliplat®
DIASP
Derivatives study
Roll rate p
Pitch rate q
Dynamic derivatives (p q r): Cl_p ; Cn_p ; Cy_p; CL_q ; Cm_q ; Cn_r ; Cy_r ;Cl_r
Property of Dept. Of Aerospace Eng., Politecnico di Torino. All rights reserved
DIASP
Conclusions
• Vsaero is an excellent tool in order to design the best
package to fulfil the design targets.
• Good correlation between numeric and experimental data.
• calculation quickness