Fluid Mechanics

Factors that reduce and increase drag

Examples

Dynamic fluid force

Bernoulli's principle

Speed Skier

Cyclist

Race car

Discus

Drag and lift (two fluid forces)

Movement of liquids and gases

Drag force:

Form Drag

Surface Drag

Skin drag

Swimmers shave body hair to reduce surface drag

Relates to friction between surface of an object and it's fluid environment

shape drag

Relates to stream lining

Impact of a fluid on an object

Cross sectional area of the moving body

Shape and surface characteristics

Velocity of moving body

Increased velocity = increased drag force

can reduce and increase drag

Larger area = Increased drag

Less streamlined= more drag and greater effect of air resistance

More streamlined= Less drag

smaller area = reduced drag

Negative lift force = (Down force)

Describes how an upward lift force is created

distribution of air pressure can cause an upward or downward force

faster the air moves= less pressure

Pressure gradient high to low

distance of air travelled has an impact as well further distance means faster travelling