8/12/2019 Applications of Bernoullis Principle
1/12
Applications of Bernoullis
PrincipleGeorgia CTAE Resource Network
Curriculum Office
Philip Ledford and Dr. Frank Flanders
8/12/2019 Applications of Bernoullis Principle
2/12
Daniel Bernoulli
Daniel Bernoulli was a Dutch-Swiss mathematician who is most knownfor his work in fluid mechanics and for his boom Hydrodynamica.
Bernoulli came up with the equitation
where:
is the fluid flow speedat a point on a streamline,
is the acceleration due to gravity,
is the elevationof the point above a reference plane, with the
positive z-direction pointing upward so in the direction opposite tothe gravitational acceleration,
is the pressureat the point, and
is the densityof the fluid at all points in the fluid.
http://en.wikipedia.org/wiki/Speedhttp://en.wikipedia.org/wiki/Earth%27s_gravityhttp://en.wikipedia.org/wiki/Elevationhttp://en.wikipedia.org/wiki/Pressurehttp://en.wikipedia.org/wiki/Densityhttp://en.wikipedia.org/wiki/Densityhttp://en.wikipedia.org/wiki/Pressurehttp://en.wikipedia.org/wiki/Elevationhttp://en.wikipedia.org/wiki/Earth%27s_gravityhttp://en.wikipedia.org/wiki/Speed8/12/2019 Applications of Bernoullis Principle
3/12
Bernoullis Equation
What does it mean?
In a simplified non-mathematical explanation, Bernoullis equation
basically means that if velocity(the speed of motion) of a fluidincreases, the pressurewithin (the force per unit area applied toan object) the fluid decreases.
Bernoullis principle is used in aerodynamics and help explains howairplane get lift, and how race cars stay on the ground. It also hasuses in lots of different machines such as a Hozon for agriculturaluse.
8/12/2019 Applications of Bernoullis Principle
4/12
HozonSiphon Mixer
A Hozon siphon mixer is used agriculturally
to fertilize plants.
This device operates somewhat with
Bernoullis principle.
Water flows through the device at a certain
velocity. As you can see the water flows
over tube where fertilizer is projected intothe water.
8/12/2019 Applications of Bernoullis Principle
5/12
HozonSiphon Mixer (cont)
This is where Bernoullis principle steps in.
Because the water is flowing over the topof the fertilizer tube it creates pressure
around the stream of moving water.
This pressure around the stream of watercauses the fertilizer to be projected
upwards towards the stream of water.
8/12/2019 Applications of Bernoullis Principle
6/12
HozonSiphon Mixer (cont)
Why doesnt the water just
spray into the fertilizer tube?
The pressure of the stream is very
low since its velocity is very high.
But, the velocity around the out side
of the stream of water is very low,
thus causing the pressure outside
the stream of water to be very high.
The high pressure that is projecting
fertilizer into the water doesnt allow
the water to enter the fertilizer tube.
8/12/2019 Applications of Bernoullis Principle
7/12
Racecars!
Racecars designs such as the ones the perform in the Indianapolis 500 use Bernoullisprinciple to keep the car on the ground, and allow the car to make sharper turns.
Notice the shape of the
spoiler.
The spoiler starts out thin
and gradually curves
upward.
This causes the velocity to
decrease and pressure to
increase on the top.
8/12/2019 Applications of Bernoullis Principle
8/12
8/12/2019 Applications of Bernoullis Principle
9/12
Airplanes
Notice the shape of the
airplanes wings.
They are shapedopposite of a racecars
spoiler.
The top of an airplanes wings are shaped so that the velocity of air moves faster
over the top and slower on the bottom. Since the velocity of air is faster on top that
means the pressure on top is low. The velocity of air is slower on the bottom so the
pressure on bottom is greater helping give lift (the force that pulls an object outward,
or upward.)to the airplane keeping it up in the air.
8/12/2019 Applications of Bernoullis Principle
10/12
Airplane Wing
The top of an airplanes wing is shaped so
that the velocity of air moves faster over
the top and slower on the bottom. Since
the velocity of air is faster on top that
means the pressure on top is low.
The velocity of air is slower on the bottom
so the pressure on bottom is greater
helping give lift to the airplane keeping it
up in the air.
* The same concept of low velocity and high pressure on the bottom of an
airplanes wings also applies to the wings of flying birds.
8/12/2019 Applications of Bernoullis Principle
11/12
Summary
What did we learn?
Daniel Bernoulli was a Dutch-Swiss mathematician who came up
with the principle of fluid mechanics known as Bernoullis Principle.
Bernoullis principle basically states that as a fluids velocity
increases the pressure within that fluid decreases.
8/12/2019 Applications of Bernoullis Principle
12/12
Summary (cont)
Devices such as Hozon siphon mixers use Bernoullis principle tocause fertilizer to mix with water by the pressure of the water it isbeing mixed with.
Racecars use a spoiler shaped so that pressure stays on top of thecar holding down.
Airplane wings are shaped opposite of racecars to have pressure onthe bottom of the wing to give it lift.