Fluid Mechanics and Physical Activity

Question 1

Laminar Flow

Answer 1

• Flow of a fluid past an object where the fluid flows in continuous lines or layers
• Low velocity, streamlined objects.

Question 2

Turbulent Flow

Answer 2

• Random, chaotic, multidimensional changes in momentum, pressure and velocity.
• Usually behind objects at high velocity.

Question 3

Eddies

Answer 3

• Swirls and reverse currents that occur when a liquid or gas flows past an obstruction.

Question 4

Vortex

Answer 4

• Formed when fluids are stirred

- Spinning action around an imaginary axis

Question 5

Wakes

Answer 5

• Area directly behind an object moving through a fluid

- Creates almost waves behind, seen on boats.

Question 6

Drag

Answer 6

• Fluid friction force
• Opposite in direction to the body or object
• The faster you move, the more drag.
• Total drag = pressure drag + surface drag + wave drag

Question 7

Slipstreaming

Answer 7

• Positioning oneself behind another object while in motion so that you are in its turbulent flow.
• The air resistance is not felt and you are in fact pulled along by the object in front.

Question 8

Bernoulli’s Principle

Answer 8

• Pressure moves from HIGH > LOW
• Fast flow, pressure low
• Creates lift on airplane wings etc.

Question 9

The Magnus Effect

Answer 9

• Spin on ball causes it to shift direction
• The air moves from high to low and so the ball follows suit
• The velocity of air particles on one side of the ball is faster than the other.
• Surface drag of ball drags air particles with it.