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after Nachtigall, 1978

after Nachtigall, 1978. ‘Quasi-steady’ analysis (blade element theory). total force. wind tunnel. lift n. drag n. U. C L. a n. U n. a n. C D. 1.0. C L. 0.5. C D. lift n = ½ C L ( a n ) U n 2 r S. 0. N. 0. 0.5. 1.0. drag n = ½ C D ( a n ) U n 2 r S. lift = S lift n.

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after Nachtigall, 1978

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  1. after Nachtigall, 1978

  2. ‘Quasi-steady’ analysis (blade element theory) total force wind tunnel liftn dragn U CL an Un an CD 1.0 CL 0.5 CD liftn = ½ CL (an) Un2r S 0 N 0 0.5 1.0 dragn = ½ CD (an) Un2r S lift = S liftn N drag = S dragn

  3. 3 2 locust c f fruit fly 1 c f crane fly 0 lift coefficient 1 - 0 1 2 3 4 drag coefficient range needed to support flight 1.3 0.8

  4. 2D wing model at 45o angle of attack leading edge vortex leading edge direction of motion trailing edge

  5. early late increase from leading edge vortex early value required For QSBE 2p late F

  6. Start of motion at low angle of attack

  7. Start of motion at high angle of attack

  8. leading edge vortex

  9. RoboFly

  10. DPIV and force measurement

  11. DPIV and force measurement

  12. 2D translating flat plate 3D revolving flat plate at low Re leading edge vortex prolonged attachment Karman street

  13. Ftrans lift total 3 . 5 a 3 . 0 CD drag U 2 . 5 2 . 0 3.0 CL 45o 1 . 5 force coefficients 1.5 1 . 0 CL 0 -9o 0 . 5 -1.5 0 . 0 3.0 45o - 0 . 5 1.5 - 9 0 9 1 8 2 7 3 6 4 5 5 4 6 3 7 2 8 1 9 0 CD -9o 0 angle of attack (degs) -1.5 0 1 2 3 time (secs)

  14. 3 flapping model fruit fly 2 1.8 locust 1.3 c f fruit fly 1 0.8 c f crane fly 0 lift coefficient 1 - 0 1 2 3 4 drag coefficient

  15. vs. u 3 constant angular velocity (72 deg/sec) 2 CL 1 0 constant forward velocity (0.157 m/s) -1 0 1 2 3 4 CD

  16. Translating model 3D wing at 45o angle of attack, Re 110 David Lentink

  17. Revolving motion 3D model at 45o angle of attack, Re 110 David Lentink

  18. downstroke 3 2 1 upstroke 4 1.delayed stall 2.rotational lift 3. stroke reversal 4.wake capture &added mass

  19. down up translational quasi-steady 1.5 measured force 1.0 net force (10-5 N) 0.5 0 down up stroke cycle

  20. Altschuler, et al., 2005 PNAS

  21. Dear Prof. Dickinson, July 28, 2006 I report on aviation for The Wall Street Journal and wonder if I could trouble you for a professional judgment. Some entrepreneurs attempting to build a large commercial aircraft with small flapping wings have approached me to write a story about their project, and I'm trying to get a sense of whether their idea is at all realistic. They say their design is based, in part, on your research and development work. But obviously there is a huge difference between simulating a tiny insect and building a 100-passenger aircraft. The company is called JCR Technology, in case you have come across them. Their website, which so far seems only to be in French, has information about their design and some computer-graphic simulations. Would you or someone in your lab have a few minutes to look at this and assess whether it is realistic to develop or simply to far-fetched? I would be happy to call to discuss your work more, and how it has prompted this idea. Best regards, Dan Michaels

  22. http://www.jcrtechnology.com

  23. http://www.jcrtechnology.com

  24. Integrative Approach sensory systems sensory feedback central nervous system motor commands mechano- sensory musculoskeletal system vision kinematics & forces olfaction dynamics& environment Behavior

  25. Eyes (8800 cells) image & optic flow sensor Wing Sensors (1000 cells) wing loading and contact Ocelli (300 cells) light-based orientation Antennae (2000 cells) olfaction, hearing, airspeed Halteres (900 cells) angular rate gyroscope sensory system of flies Each wing stroke, the fly’s brain integrates input from 15,000 cells. 0.5 mm

  26. infrared sensitive cameras fabric enclosure infrared light 1200 angular velocity (o s-1) 0 1m 10 sec -1200 side view side view top view 5000 frames/sec, 150 msec duration Tammero&Dickinson, JEB 2002, Mark Fry, Ros Sayamen

  27. visual feedback

  28. 50 50% 50% number 25 ~90o ~90o 0 -90 0 +90 saccade angle Saccades are triggered by visual input. Tammero&Dickinson, JEB 2002a

  29. flight arena “fly’s eye view” Flies turn away from expansion. Tammero&Dickinson, JEB 2002a

  30. fly angular velocity of stripe left- right stroke amplitude gain ‘closed-loop’ flight simulators IR diode LED display wingbeat analyzer

  31. Stripe Fixation Michael Reiser

  32. fixation/expansion

  33. center left right summary of expansion reflexes

  34. musculoskeletalmechanics

  35. downstroke muscles upstroke muscles power muscles

  36. b1(first basalar) steering muscles

  37. b1 50 ms wing motion

  38. phaseadvance phasedelay steering muscle control

  39. aerodynamics

  40. high speed camera IR LED panel visual target flight path

  41. 2) tilt of stroke plane 30 degs 1) increase in stroke amplitude 0.25 1.0 yaw torque (10-8 Nm) kinematics changes during saccades

  42. torque to turn left right counter-torque to stop turning What triggers counter-turn?

  43. mechanosensory feedback

  44. magnet N IR camera LED arena S CPU N mirror magnet S magnetictether

  45. eyes halteres ‘loose’ saccades vs. ‘rigid’ saccades torque with rigid tether angular velocity with loose tether 400 os -1 100 ms 5x10-9 nNm

  46. pitch Coriolis force sensor arrays halteres

  47. 150 orientation (deg) 100 50 stimulus fly 0 0 100 200 300 400 500 time (ms)

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