1 / 24

Introduction to Fluid Mechanics

Introduction to Fluid Mechanics. Bellagio Fountain. Lecture 9: Introduction to Fluid Mechanics Approximate Running Time - 33 minutes Distance Learning / Online Instructional Presentation Presented by Department of Mechanical Engineering Baylor University Procedures:

masao
Download Presentation

Introduction to Fluid Mechanics

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. Introduction to Fluid Mechanics Bellagio Fountain

  2. Lecture 9: • Introduction to Fluid Mechanics • Approximate Running Time - 33 minutes • Distance Learning / Online Instructional Presentation • Presented by • Department of Mechanical Engineering • Baylor University • Procedures: • Select “Slide Show” with the menu: Slide Show|View Show (F5 key), and hit “Enter” • You will hear “CHIMES” at the completion of the audio portion of each slide; hit the “Enter” key, or the “Page Down” key, or “Left Click” • You may exit the slide show at any time with the “Esc” key; and you may select and replay any slide, by navigating with the “Page Up/Down” keys, and then hitting “Shift+F5”.

  3. Introduction Dr. Carolyn Skurla Speaking

  4. Aerodynamics Forces On An Airplane • What causes drag and lift? ldaps.ivv.nasa.gov/physics/lift.html

  5. Drag • Drag is a function of friction • F = drag force • CD = drag coefficient •  = density of the fluid • A = characteristic area • depends on body shape • v = free-stream velocity

  6. Characteristic Area • The shape of the silhouette of the object • If you were a molecule of water flowing toward the object • And there was a light behind the object • What would the object look like to you?

  7. L d Characteristic Area • Cylinder with fluid flow perpendicular to length of cylinder?

  8. L Characteristic Area • Cylinder with fluid flow parallel to length of cylinder? d

  9. Example Problem: Drag L r

  10. Example Problem: Drag L r

  11. Drag On A Cylinder - Why? No Flow Separation Stagnation Point Stagnation Point

  12. Friction, that’s why! Drag On A Cylinder

  13. Which Has More Drag?

  14. Better streamlining of cars over the years Lower drag force & better fuel efficiency! Why Do We Care About Drag?

  15. Example Of Friction http://www.dfrc.nasa.gov/gallery/photo/SR-71/

  16. Example Of Friction

  17. Fluid Exerts a Force • Drag -> Acts in the direction opposite to the motion of the object. • Lift -> Acts at right angles to the drag. (http://www.titleist.com/technology/aerodynamics.asp)

  18. Example of Lift • Lift caused by pressure differential between top and bottom of wing. ldaps.ivv.nasa.gov/physics/lift.html

  19. How Does a Curveball Work? • A spinning ball curves in flight • Magnus effect • Stitches are NOT required to make a baseball curve http://popularmechanics.com/science/sports/1997/4/breaking_pitch/print.phtml

  20. Lift On A Golf Ball • How does a golf ball generate lift? (www.titleist.com/htm/tech/aero_main.asp)

  21. Why are Golf Balls Dimpled? Dimples No Dimples (www.titleist.com/htm/tech/aero_main.asp)

  22. Drag Force on Dimpled vs. Smooth Golf Balls • Dimpled golf balls generate less drag! • Increases angle of separation for transition to turbulence. (www.titleist.com/htm/tech/aero_main.asp)

  23. Lift Force on Dimpled vs. Smooth Golf Balls • Backspin generates lift! • Dimpled golf balls have slightly improved lift. (www.titleist.com/htm/tech/aero_main.asp)

  24. This Concludes Lecture 9

More Related