Download presentation

Presentation is loading. Please wait.

Published byMarley Canter Modified over 2 years ago

1
The Aerodynamics of Baseball April 18, 2009

2
Outline Background Basic Physics of Flight Fly Ball Pitched Ball Questions

3
Why NASA? Computational Fluid Dynamics Glenn Research Center

4
Why NASA? Educational Outreach Beginner’s Guide to Aeronautics Glenn Research Center

5
Why NASA? Glenn Research Center

6
Physics of Flight Objects Respond to External Forces Newton’s Laws of Motion Glenn Research Center

7
Forces A Force is a Push or a Pull A Force is a Vector Quantity Vectors: Velocity, Acceleration, Displacement, Force Scalars: Temperature, Pressure, Density, Mass Volume, Length, Area, Kinetic Energy, … Magnitude (Size) Direction VectorsScalars Magnitude only Glenn Research Center

8
Forces in Flight Flight Velocity Weight Lift Drag Aerodynamics Center of Gravity Center of Pressure Glenn Research Center

9
Weight Glenn Research Center W = m g Baseball Rule Book Weight = 5 oz (actually 5/16 lb) Diameter = 2.875 to 3 inches

10
Motion in Flight Flight Velocity Weight Neglect Aerodynamics Glenn Research Center F = m a a = F m v = g t + v 0 d = g t + v t + d 0 0 2 2 Newton’s 2 nd Law F = W = m g (constant mass) = g

11
V L V = V cos (a) Lo a U = V sin (a) oL

12
HitModeler http://www.grc.nasa.gov/WWW/K-12/airplane/hitmod.html

13
Fly Ball Results Glenn Research Center SpeedAngleDistanceDragLocationTempPress 10045 --- 0 Wind - 669

14
Properties Glenn Research Center Air Nitrogen N 78% Oxygen O 21% Traces - CO - H O - … Mixture of Gases 2 2 2 2 Molecules in constant motion Collide with each other and container Mass (m) -> Density Momentum (m V) -> Pressure Kinetic Energy (m V ) -> Temperature 2 Viscosity, Compressibility

15
Aerodynamic Drag Velocity V Aerodynamic Drag Sir George Cayley Glenn Research Center 2 2 D = Cd V A F ~ V A Shape - Inclination - Viscosity Size - Area A Air Density Viscosity Shape Modern Drag Equation 2 Cd = Coefficient contains effects of Shape – Viscosity Dynamic Pressure depends on state of the gas (pressure & temperature) V 2 2 =

16
Motion in Flight Include Aerodynamic Drag Glenn Research Center Problem #1 Solution: Slight rotation of the ball pins the separation point Time Drag Flow past a ball is highly unsteady and can become chaotic

17
Motion in Flight Include Aerodynamics Glenn Research Center Problem #2 Drag Coefficient for a Spinning Ball Depends on Viscosity & Surface Details Re x 101.010.0 Reynolds Number = Re = Viscous Force Inertial Forces = V d Cd,5,3,1 Smooth Ball Baseball -5 Cd =.3 Baseball

18
Motion in Flight Include Aerodynamic Drag Glenn Research Center V = a t + V 0 Problem #3 F = W - D = m a Can’t use simplified Newton’s 2 nd Law D = function of V 2 Must Solve: dV 2 W C V A dt 2 m = - 2 d dV dt = F m

19
HitModeler http://www.grc.nasa.gov/WWW/K-12/airplane/hitmod.html

20
Glenn Research Center SpeedAngleDistanceDragLocationTempPress 10045 --- 0 Wind - 669 10045Cleve60290.3378 Fly Ball Results

21
Glenn Research Center SpeedAngleDistanceDragLocationTempPress 10045 --- 0 Wind - 669 10045Cleve60290.3378 10045Cleve80290.3385 Fly Ball Results

22
Glenn Research Center SpeedAngleDistanceDragLocationTempPress 10045 --- 0 Wind - 669 10045Cleve60290.3378 10045Cleve80290.3385 10045Cleve32290.3370 Fly Ball Results

23
Glenn Research Center SpeedAngleDistanceDragLocationTempPress 10045 --- 0 Wind - 669 10045Cleve60290.3378 10045Cleve80290.3385 10045Cleve32290.3370 10045Cleve60280.3384 Fly Ball Results

24
Glenn Research Center SpeedAngleDistanceDragLocationTempPress 10045 --- 0 Wind - 669 10045Cleve60290.3378 10045Cleve80290.3385 10045Cleve32290.3370 10045Cleve60280.3384 10045Cleve6029+5.3410 Fly Ball Results

25
Glenn Research Center SpeedAngleDistanceDragLocationTempPress 10045 --- 0 Wind - 669 10045Cleve60290.3378 10045Cleve80290.3385 10045Cleve32290.3370 10045Cleve60280.3384 10045Cleve6029+5.3410 10045Cleve6029 -5.3338 Fly Ball Results

26
Glenn Research Center SpeedAngleDistanceDragLocationTempPress 10045 --- 0 Wind - 669 10045Cleve60290.3378 10045Cleve80290.3385 10045Cleve32290.3370 10045Cleve60280.3384 10045Cleve6029+5.3410 10045Cleve6029 -5.3338 10045Denver6024 0.3404 Fly Ball Results

27
Aerodynamic Lift Velocity V Aerodynamic Lift Sir George Cayley Glenn Research Center 2 2 L = Cl V A F ~ V A Shape - Inclination - Viscosity Size - Area A Air Density Viscosity Shape Modern Lift Equation 2 Cl = Coefficient contains effects of Shape – Spin - Viscosity Dynamic Pressure depends on state of the gas (pressure & temperature) V 2 2 = Spin

28
Flow Moving with ball

31
Aerodynamic Lift Velocity V Ideal Lift Glenn Research Center 2 L = Cl L ideal L ideal = N d d s V Size - Diameter d Air Density Viscosity Shape Lift Equation Cl = Coefficient contains effects of Shape - Viscosity Spin - s Aerodynamic Lift Cl =.15 N = numerical factor

32
Ideal Trajectory

33
http://www.grc.nasa.gov/WWW/K-12/airplane/foilb.html

35
Some Curve Ball Results Glenn Research Center A) 100 mph fast ball crosses plate in.44 sec drops almost 3 feet from the pitcher’s hand B) Curve ball (80 mph – 2000 rpm – axis vertical – Cleveland).54 sec - 20 inches side-to-side - drops 4.5 feet C)Same as B except Hot Day (90 degrees) – loses 1.1 inch Same as B except Cold Day (34 degrees) – adds 1.2 inch D) Same as B except axis horizontal – no side-to side ball drops 3 feet or 6 feet depending on orientation No rising fastball (would need about 5000 rpm) E) Changing axis between B & D gives large variation

36
Some Curve Ball Results Glenn Research Center A) Curve ball (80 mph – 2000 rpm – axis vertical – Cleveland).54 sec - 20 inches side-to-side - drops 4.5 feet B) Same as A except Denver (25 in Hg vs 29 in Hg) loses 3.1 inches side-to-side Denver is a bad place to pitch and a good place to hit! C)A 100 mph fastball crosses the plate at 94 mph in Cleveland, 96 mph in Denver

37
Conclusions Glenn Research Center A) Aerodynamics has a big effect on the game of baseball B) Understanding these effects explain observations about different ballparks and different pitchers / hitters at various times during the season and post-season C) Software is available for you to learn some more about baseball and aerodynamics. You can play on-line or download the software (Java source is supplied). Search on “ NASA Baseball” D) GO TRIBE !!

38
Advertisements Glenn Research Center A) May 13 and May 28 - WKYC Weather Days B)June 27 – 28 NASA Days with the Tribe special Kid’s events and exhibits C)GO TRIBE !! Questions?

39
Backups

41
Time Drag Drag of a smooth ball ---- Knuckle Ball

42
Glenn Research Center SpeedAngleDistanceDragLocationTempPress 10045 --- 0 Wind - 669 10045Cleve60290.3378 10045Cleve90290.3387 10045Cleve35290.3370 10045Cleve60280.3384 10045Cleve6029+5.3417 10045Cleve6029 -5.3338 10045Denver6024 0.3405 Fly Ball Results

Similar presentations

OK

Vectors and Scalars Scalars have magnitude only e.g. mass, speed, distance Vectors have magnitude and direction e.g. force of 10 N to the left.. Velocity,

Vectors and Scalars Scalars have magnitude only e.g. mass, speed, distance Vectors have magnitude and direction e.g. force of 10 N to the left.. Velocity,

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on field study in education Ppt on how to improve your communication skills Ppt on mathematical games Ppt on natural resources in india Ppt on gulliver's travels part 3 and 4 Ppt on introduction to production management Ppt on gunn diode oscillators Sap procure to pay ppt online Short ppt on social media Ppt on direct broadcasting satellite