DIASPMeeting #6
Turin 4-5 February 2003
““The Use of The Use of VSAeroVSAero CFD Tool in the UAV CFD Tool in the UAV Aerodynamic ProjectAerodynamic Project ““
Alberto PORTO – Massimiliano FONTANAPorto Porto Ricerca Ricerca FDSFDS
Giulio ROMEO - Enrico CESTINO – Giacomo FRULLAPolitecnico di Torino, Dept. of Aerospace Eng.
Porto RicercaDIASP
S.n.c.Monza, (Milano)
Italy
• Providers of CFD Software• Engineering Research • Consulting Services
DIASP Flow Analysis ComponentsGRID
GENERATIONAMIGRID
SPINGRIDALL
Property of Dept. Of Aerospace Eng., Politecnico di Torino. All rights reserved
FLOW SOLUTION
VSAEROUSAEROMGAERONSAERO
POST PROCESSINGOMNIPLOT
OMNI3DTECPLOT
CAD
DIASP VSAEROSubsonic, Quasi-Steady Flow
Integral Panel/Boundary Layer Method
Complex Geometries Thick and Vortex Lattice Surfaces
Wake Modeling
Performance
Stability and Control
Boeing 727-200
• Lateral Symmetry• 4100 Body Panels• 3900 Wake Panels• 1 Wake Iteration• 3 Viscous Iterations• CPU Requirement:
SGI 4D/35 (R3000) 1.5 Hours
SGI (R10000) 5 Minutes
Boeing 727-200
Akron - AirshipDIASP
the modified Stratford criteria the modified Stratford criteria of Mendenhall35 have been of Mendenhall35 have been
added to VSAERO to find the added to VSAERO to find the cross flow separation line.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
-2
-1
0
1
2
3
4
5
6
0 0.5 1 1.5 2 2.5 3 3.5
S p e e d
Dif. Vs aero
0.94
0.95
0.96
0.97
0.98
0.99
1
1.01
1.02
0 1 2 3 4 5 6 7 8 9 10S p e e d
AC-b aseAC-2 VsaeroAC-2 Tank tes t
% error in drag
vs. speed for the
an upwind
case
Percentage difference in drag on
two different Americas
Cup yachts calculated
with VSAERO and tested in a towing
tank.
CFD Wave height calculation
ASI & EC (Helinet) projects
Span:73m; TOGM:750kg; Mass PL:100kgPower PL:1kW; Req. Power=6 kW; TAS=71 km/h; Altitude: 17km;Endurance: 6 monthsEffic. s.c.:20%; Effic. f.c.+elect:60%
Heliplat® Solar-powered UAV
® 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 POLITO / ARCHEMIDE
® Trademark of Dept. of Aerospace Engineering of Politecnico di Torino 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
DIASP
® Trademark of Dept. of Aerospace Engineering of Politecnico di Torino
Heliplat®
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 E216 show a better compromise between the compromise between the
airfoil Drag and the airfoil Drag and the induced wing Drag induced wing Drag
DIASP Heliplat®Wing airfoil geometry–2D XFOIL optimization
thickness effect
camber effect
® Trademark of Dept. of Aerospace Engineering of Politecnico di Torino
combined effect
Heliplat®
Property of Dept. Of Aerospace Eng., Politecnico di Torino. All rights reserved
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.
Aerodynamics Efficiency
30
32
34
36
38
40
42
44
46
48
50
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8
CL
E Rectangular Wing- FX 63137
PIANTA0- FX 63137
PIANTA0- E216
PIANTA0- HPF118
PIANTA8- HPF118
PIANTA8 twisted- HPF118 family
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.
Property of Dept. Of Aerospace Eng., Politecnico di Torino. All rights reserved
Heliplat®
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
CP Cf visualization all over the Airplane
Heliplat®DIASP
Property of Dept. Of Aerospace Eng., Politecnico di Torino. All rights reserved
Accurate pressure distribution on Heliplat complete configuratioAccurate pressure distribution on Heliplat complete configuration n CP Station cutCP Station cut
CP CP buttline buttline cutcut
Heliplat®
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
Property of Dept. Of Aerospace Eng., Politecnico di Torino. All rights reserved
® Trademark of Dept. of Aerospace Engineering of Politecnico di Torino
Heliplat®Propeller - analysis
Skin friction coefficient
Property of Dept. Of Aerospace Eng., Politecnico di Torino. All rights reserved
Aileron Stabilizer Rudder
Static derivatives Cm_δe ; CL_δe ; CFy_δa ; Cl_δa ; Cn_δa ; CFy_δr ; Cl_δr ; Cn_δr
Derivatives study
Heliplat®DIASP
Property of Dept. Of Aerospace Eng., Politecnico di Torino. All rights reserved
Derivatives study
Roll rate p
Heliplat®DIASP
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
DIASPConclusions
• 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