1. Wind tunnel visualization of air flow AIR streamlines

2. The black lines are the paths that the fluid takes as it flows. Wider spacing indicates low speed flow, narrow spacing indicates high speed flow Color indicates pressure High Low pressure Streamlines and fluid flow

3. Figure 11-29

4. Streamlines around a wing wing

5. Airflow around a baseball that is NOT spinning The ball is moving but from the ball’s perspective the air moves relative to the ball The streamlines are bunched at the top and bottom indicating higher flow speed The pressure forces are balanced

6. Curveballs low speed, high P The ball is rotating clockwise. The layer of air adjacent to the ball is dragged along by the rotation, causing the flow speed to be higher on the top side. The higher pressure on the bottom causes the ball to curve upward. High speed, Low P the lift on a rotating body moving through a fluid is called the MAGNUS FORCE

7. Curveballs low speed, high P The ball is rotating clockwise. The layer of air adjacent to the ball is dragged along by the rotation, causing the flow speed to be higher on the top side. The higher pressure on the bottom causes the ball to curve upward. High speed, Low P the lift on a rotating body moving through a fluid is called the MAGNUS FORCE

8. Pitch drop experiment at the University of Queensland in Brisbane, Australia Pitch- used as a roofing material to prevent leaks Must be heated to be applied viscosity ~ 10 11 water Experiment began in 1927 8 drops have since fallen, one every decade or so