Fluid Mechanics

Question 1

fluid forces related to what two situations?

Answer 1

1. the object is still and the fluid is moving

2. the object is moving and the fluid is still

Question 2

surface drag

Answer 2

friction between the surface of the object and moving fluid

Question 3

form drag

Answer 3

resistive force created by the impact of the molecules as the object moves

Question 4

Laminar Flow

Answer 4

particles separate and reform behind the object - slow moving objects

Question 5

Profile Drag

Answer 5

Resistive drag that is created by an area of high pressure and an area of low pressure
- resistance increases as relative velocity increases

Question 6

lift force

Answer 6

perpendicular force generated from fluid moving over/around a projectile or object

Question 7

Bernoulli’s Principle

Answer 7

high velocity flow = low pressure region
low velocity = high pressure region
- lift force pushed in the direction of the low pressure region

Question 8

Magnus Effect

Answer 8

Lift force directed from high pressure to low pressure region

• zones of high and low pressure are created by spinning the ball
• air moves faster in direction of spin and is slowed when spin resists flow of air

Question 9

Magnus Force:

Answer 9

spinning projectile deviates progressively in the direction of the spin

Question 10

Slice

Answer 10

extreme rightward movement, magnus affect reduces forward distance and creates more lateral deflection

Question 11

fade

Answer 11

slight slice

Question 12

hook

Answer 12

extreme leftward deflection

Question 13

Draw

Answer 13

Slight hook