Laminar and Turbulent Flow: More Practice

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Laminar and Turbulent Flow More Practice
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Bernoullis Principle

• SPH4C

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Fluid Flow

• The speed at which a fluid flows depends on the
  diameter of the pipe.
• In the diagram below, the fluid must flow more
  quickly in section B than in section A.

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Pressure Differences

• The water must accelerate as it moves from A to
  B. This acceleration must be caused by a force.
• This force is caused by the difference in
  pressure between the two regions.

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Bernoullis Principle

• Where the speed of a fluid is low, the pressure
  is high.
• Where the speed of a fluid is high, the pressure
  is low.

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Lift

• The upward force, or lift, on an airplane wing
  can be explained using Newtons 3rd Law of Motion
  and Bernoullis Principle.

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Lift and Newton

• As the wing moves forward, air deflects off the
  bottom of the wing the wing pushes on the air.
  The air therefore pushes back (the reaction
  force).

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Lift and Bernoulli

• The speed of the air near the deflection is less
  than the speed of the flow of air over the wing.
  
• Therefore the pressure under the wing is higher
  than the pressure over the wing.

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Animation

• The black dots show timelines.
• The coloured dots show streamlines.
• More on streamlining tomorrow. . . .