Numerical, Experimental and Flight Investigation of MAV Aerodynamics Sergey V. Serokhvostov Moscow Institute of Physics and Technology(MIPT), Department of Aeromechanics and Flight Engineering 16, Gagarina str., Zhukovsky, Russia, 140180 (
[email protected]) and
A.V. Kornushenko, A.V. Shustov and S.V. Lyapunov Central AeroHydrodynamical Institute (TsAGI) 1, Zhukovsky str., Zhukovsky, Russia, 140180
PURPOSES 1. Investigate the influence of MAV wing shape on aerodynamical characteristics 2. Investigate the influence of profile shape and winglets on aerodynamical MAV characteristics 3. Investigate the influence of powerplant on aerodynamical MAV characteristics 4. Investigate the influence whole MAV design on aerodynamical MAV characteristics 5. Investigate possibility of numerical investigation of pressure distribution 6. Compare the results of wing tunnel and flight experiments
WING TUNNEL AND EXPERIMENTAL MODELS
Wing 1
Wing 2
Wing 3
Wing 4
Wing 5
=1.5
=1.92
=1.7
=1.76
=1.82
Wing 1
Wing 7
Wing 8
Wing 9
flate plane
profile
profile, flexible
profile, winglets
WIND TUNNEL EXPERIMENTS Influence of wing shape investigation Wing 1
Wing 2
Wing 3
Wing 4
Wing 5
=1.5
=1.92
=1.7
=1.76
=1.82
Wings with the same wing span DRAG coefficient vs. LIFT coefficient
DRAG vs. LIFT
Drag for the same lift is independent of wing shape for moderate CL
WIND TUNNEL EXPERIMENTS Influence of wing shape investigation “Energetic” characteristics (POWER)-1 coefficient vs. LIFT coefficient
(POWER)-1 vs. LIFT
WIND TUNNEL EXPERIMENTS Influence of profile investigation Wing 1
flate plane
Wing 7
Wing 8
profile
profile, flexible
Wing 9
profile, winglets
Curved and flexible profile gives some advantage in comparison with rigid flat plane. Winglets are effective for CL>0.3
WIND TUNNEL EXPERIMENTS Influence of propeller investigation
Flow from powerplant allows to obtain higher values of CL. Polar curves are the same up to separation
WIND TUNNEL EXPERIMENTS Characteristics of the whole MAV
Empennage, additional parts and devices decrease maximum of L/D up to about 20%
NUMERICAL INVESTIGATIONS Pressure distribution
Red line – XFoil with fixed transition location, blue line – XFoil with free transition location, small circles – experiment results
XFoil can be used for the pressure distribution and separation localization
FLIGHT EXPERIMENTS
SEPARATION OCCURS ONLY ON THE WING TIPS DURING THE LEVEL FLIGHT!
CONCLUSIONS The results obtained allow to make some conclusions. 1. XFoil program can be used to determine the location of separation bubble. 2. All the wing with the same wing span give nearly the similar characteristics in the region of moderate CL. 3. Profiled wing, flexible wing can improve the MAV characteristics. Winglets are effective for CL>0.3. 4. Wind tunnel experiment results are in coincidence with real flight. 5. The separation without re-attachment on the MAV with working powerplant occurs only on the wing tips.
Acknoledgements This work was carried out under support of Russia’s President Grant for Young Scientists Support MK-5370.2006.8 and RFBR Grant (project 07-08-00820-a).