Fluid Flow Hydrodynamics Aerodynamics

1
Fluid FlowHydrodynamicsAerodynamics

• Bernoullis Principle
• Poiseuilles Law

2
Wind tunnel visualization of air flow
streamlines
AIR FLOW
3
Streamlines and fluid flow

• 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
pressure
4
Bernoullis Principle

• Fluid flow velocity v
• Fluid pressure P

? where v is high, P is low ? where v is low, P
is high
5
Blowing air over the top of the tube lowers
the air pressure on that side allowing the fluid
to rise
6
Bernoulli's Principle
7
Streamlines around a wing
From the perspective of the jet, the air is
moving past it
High speed ? low pressure
Low speed ? high pressure
8
Flow over an airplane wing
9
11.10 Applications of Bernoullis Equation
10
11.11 Viscous Flow
POISEUILLES LAW The volume flow rate is given
by
h is a constant called the viscosity- it is a
measure of the resistance of the liquid to
flowing (i. e., thickness)
11
POISEUILLES LAW