1 / 65

Mingyu Kang

Problem # 5. Levitation. Mingyu Kang. Team Korea. Phenomenon. Investigate the effect Oscillation Produce the maximum angle of tilt. Force Analysis. Bernoulli. Coanda. Flow Chart. -Oscillation . -Oscillation . Airstream Velocity Profile. Optimization ( Maximum angle of tilt).

macon
Download Presentation

Mingyu Kang

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Problem #5 Levitation Mingyu Kang Team Korea

  2. Phenomenon • Investigate the effect • Oscillation • Produce the maximum angle of tilt

  3. Force Analysis Bernoulli Coanda

  4. Flow Chart -Oscillation -Oscillation Airstream Velocity Profile Optimization (Maximum angle of tilt) Drag force Gravity Bernoulli effect Coanda effect (Boundary layer thickness) Momentum flow conservation Gaussian curve distribution Force equilibrium Airstream velocity Mass of ball Oscillation period -Equilibrium Point Oscillation period -Equilibrium Point Pitot tube experiment

  5. Free Airstream Velocity Profile

  6. Momentum flow conservation of free jet Free jet: Momentum flow is a CONSERVED quantity

  7. Velocity at the Center Assume that the velocity is even at the narrow area of the center. By momentum flow conservation

  8. Experiment: Velocity at the Center Pitot tube anemoemeter

  9. Result

  10. Result

  11. Velocity Profile: Gaussian Curve By momentum flow conservation Assume Gaussian curve profile:

  12. Experiment: Velocity Profile

  13. Result

  14. Error Airstream velocity at the opening is weaker at the edge!

  15. Velocity at the Opening

  16. Experiment

  17. Experimental Setting

  18. JAVA Image Processing

  19. Controlling the Mass of the Ball Clay

  20. Drag Force and - Oscillation

  21. Drag Force

  22. - Oscillation Model , ,

  23. Theory: - Oscillation

  24. Experiment: - Oscillation s

  25. Theory: y-Equilibrium Position

  26. Experiment: -Equilibrium Position Cause of Error Gaussian curve assumption Compression effect

  27. Compression of the Airstream When -displacement is low……

  28. Experiment Setting: Compression of the Airstream Force sensor

  29. Experiment Result: Compression of the Airstream Compression!

  30. Pressure Force and - oscillation

  31. Bernoulli Effect

  32. Bernoulli Effect

  33. Coanda Effect

  34. How thick is ? Viscous force No-slip Condition Boundary Layer Thickness ( : kinematic viscosity )

  35. Coanda Effect :

  36. Coanda Effect : Bernoulli effect is the major one!

  37. -Oscillation Model , ,

  38. Theory: -Oscillation

  39. Experiment: -Oscillation s

  40. Experiment:-Equilibrium Position

  41. Motion of the Ball Experiment Theory

  42. Optimization

  43. Theory: Optimization , that achieves ⇒ OPTIMIZATION!

  44. Airstream velocity optimization

  45. Mass of the ball Optimization

  46. Experiment: Optimization Maximum Angle of Tilt

  47. Experiment: Optimization m/s

  48. Conclusion Velocity Profile Gaussian Curve & Momentum flow Conservation - Oscillation Drag Force - Oscillation Bernoulli + Coanda Pressure Force Optimization ,

  49. Thank You!

  50. Spin of the ball 0.74rev/s=4.65rad/s m/s 8.5m/s (airstream velocity at equilibrium point) Irregular direction Small rotation speed NEGLIGENT!

More Related