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Aerodynamics
*This packet is intended for elementary schools, to be used in groups of
three or fewer and/or individually.
In this packet, we will be learning the basic physics behind how air balloons, airships,
and airplanes fly! We are then going to practice these principles in easy and fun
activities that can be done in the classroom or at home.
Contact the National Museum of the U.S. Navy
for Field Trip and School Visit opportunities!
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History of Flight in the United States Navy
In 1910, Captain Washington Irving Chambers, who worked
for the Navy’s Bureau of Equipment attended an aviation
meeting near Baltimore as an official observer. Appreciating
the potential value of the airplane in naval warfare, Captain
Chambers tried to interest the Wright Brothers, who had
successfully flown the first flight in 1903. Wilbur Wright
declined to make the attempt. Chambers then approached the
Curtiss Company, and they agreed to try flying a plane for the
Navy. The necessary arrangements were made by Captain
Chambers and on November 14, 1910, the Curtiss
representative, Eugene Ely, successfully flew a Curtiss land-
plane from a platform rapidly built on the bow of the U. S. S.
Birmingham at Hampton Roads, Virginia. The Curtiss
Company agreed to instruct several naval officers for free, as
no money had yet been permitted by Congress for the
development of naval aviation. As a result of Captain
Chambers's reports and recommendations on aviation, the
first aviation appropriation of $25,000 was included in
1911-12. Two Curtiss planes and one Wright plane were
purchased, and in the summer of 1911 the first naval aviation
unit was organized and an aviation training camp was
established at near Annapolis, Maryland.
By the beginning of the World War I, the US Navy rarely used
airplanes. Most countries used hot air balloons and airships
(zeppelins) in order to photograph enemy grounds and gain
intelligence. Most of the actual planes owned by governments
were not for warfare and didn't see the line of battle until the end of the War. Pilots started carrying bricks on
board to drop on opposing planes, and some even started carrying guns with them. The French and Germans
became well known for their Aces, or talented pilots, like Manfred von Richthofen (Red Baron). Pilots like
Richthofen learned to do spins, half-rolls, and climbing turns, among other flying techniques.
Naval Aviation and the nation's greatest test came with the onset of World War II. After the Japanese attack on
Pearl Harbor, 7 December 1941, the United States was thrust into the global conflict and the Navy took the lead in
the Pacific War. Naval Aviation was a key component of victory, whether in the great carrier battles with the
Imperial Japanese Navy, supporting the island-hopping campaign, or combating U-boats in the Battle of the
Atlantic. By 1945, the ranks of Naval Aviation personnel numbered over 430,000 men and women.
Today, the United States Navy operates over 3,700 airplanes which are used for anything from transportation to
surveillance. Now, let’s learn how these aircrafts fly!
Guiding Question:!
How would the US Navy use airships
and hot air balloons today?
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Hot Air Balloons
How do they work?
There are two types of aircrafts: lighter than air
and heavier than air. A hot air balloon is a “lighter
than air” aircraft, meaning, the balloon is
buoyant in the air. The balloon itself is heavier
than air, but with heat and helium, we can make
these object fly.
When hot, the molecules in air speed up, making
them move around faster. This makes for fewer
molecules in the given space, thus making it
lighter than the surrounding area. By heating the
inside of the hot air balloon with a flame,
molecules escape
the balloon
through the
bottom. We
heat up the
molecules and
make the inside
lighter than the
outside.
Let’s Test it Out!
1. Find a partner or
group to work with.
2. Tie the end of your
trash bag with the
opening in the
bottom.
3. Decorate your bag as
you wish, using light
materials like stickers and paper.
4. Pierce the bottom of your bag (the open end)
with paperclips for weight if you like.
5. With permission from a parent or adult, one person will
hold the bag up while another blows hot air under the
balloon.
6. Feel the tension from the balloon wanting to lift up into the
air. Now, carefully let go and watch your balloon lift up!
What you’ll need:
•
5 gallon or kitchen trash bag
•
paperclips (for weight)
•
Sticker or paper to decorate your
balloon
•
1 hair dryer
•
String
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Airships
How do they work?
Just like the hot air balloon, airships are
“lighter than air” aircrafts. Instead of
using heat, airships mainly use lighter
gases to lift them up in the air. Helium is
used today, just like birthday balloons. In the
past, we used hydrogen, which is also lighter
than air. Hydrogen, however, is very
flammable and can explode. Helium is not flammable.
Unlike hot air balloons, we can steer and control airships. How do
we do that? Rudders on the back of the airship help with steering
and the ballonets inside the airship control the altitude or
buoyancy. Let’s look into how we do that.
Ballonets
Rudder
Ballonets are small pockets inside the main
envelope of the airship. Air can be pumped
in or out of them with ease, and we fill them
with regular air we breathe everyday. This
air is heavier than helium, which makes up
the envelope. By adding more regular air,
the airship becomes heavier and lowers its
altitude. Sucking the regular, heavier air out
of the ballonnets allows the envelope to fill
with helium, making it lighter and able to
increase altitude.
Buoyancy:
Positive buoyancy=
Airship rises
Negative buoyancy=
Airship descends
Neutral buoyancy= Cruising Altitude
Guiding Question:!
How could submarines use this technology?
In the graphic to the right, draw the
ballonets inside the envelope.
Remember that a bigger ballonet is
heavier. Look to the graphic above as a
reference.
Where do you think people sit?
Hindenburg
Earlier, we read about how we used to use hydrogen in the envelope,
but we use helium now. This all changed on May 6, 1937, when an
airship called the Hindenburg exploded. A lot of people were hurt or
even died. While helium is a little heavier than hydrogen, we do not
want any more accidents.
Envelope
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Airships
Let’s Test it Out!
What you’ll need:
•
4 mylar-helium balloons
•
2 regular (non-helium) balloons
•
1 toilet paper roll
•
string
•
molding clay
•
construction paper
•
scissors
•
classroom glue
You can make your own airship with helium-
filled mylar balloons. You can use string and
molding clay to tether your balloons to a
surface to prevent your balloon from flying
away.
1. Cut 4 tail fins (trapezoids) from the construction paper. See the blue fins in the image as an example.
2. Cut eight pieces of string into equal lengths. Weight each string with a piece of modeling clay to either
side of the balloons to balance your airship.
3. Make your airship by gluing the mylar balloons together. Tether them down with string and modeling
clay to help.
4. Glue the tail fins (rudders) to the airship, as seen in the example, There should be 4 total, at 12:00,
3:00, 6:00, and 9:00.
5. Untether your balloons from the surface, and watch your airship rise! It is smart to keep a string
attached to it like a kite, so you don’t lose it!
6. To test out the weight of air against helium, attach the regular balloons to the front or back and see how
it tilts (buoyancy).
The US Navy had several airships, especially in
the 1930’s. One example is the USS Macon, an
airship built and operated for scouting and served
as a "flying aircraft carrier", capable of fitting
eight aircraft that could be released mid-air!
It was in service for less than two years. In
1935, the Macon was damaged in a storm and
lost off California's Big Sur coast.
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Let’s look at Isaac Newton’s Laws of Motion. How do they apply?!
•
Second Law of Motion, acceleration is produced when a force acts on
a mass. The greater the mass, the greater the amount of force
required.!
•
The Third Law of Motion states that for every force, there is a
reaction force that is equal in size, but opposite in direction.
Therefore, whenever one object pushes another
object, it gets pushed in the opposite direction
equally as hard.
Airplanes/Jets
Unlike the hot air balloon or airship, airplanes are
“heavier than air” crafts. Because of this, we use
physics, not weight, to get our
airplanes in the air. This can get a
little complicated, but let’s learn
about lift!
The shape and speed are the most
important factor when you're getting
a plane to fly. The shape of the
wing, known as an airfoil, makes
the air pressure very low on top of
the wing and high below it. We use
high speeds to change the air
pressure. When the plane speeds
up for takeoff, these speeds create
lower air pressure (fewer molecules)
above the wing. This creates lift. The curve on top of the airfoil creates this change in pressure,
mixed with speed. The molecules passing over the wing have farther to go because of this
curve. This causes the air to speed up above the wing, spreading the molecules out and lowering
the air pressure. The air below the airfoil remains the same, so the higher pressure is pushing up
on it, helping with lift.
Airfoil
We just learned about how we create lift in an airplane, but three other factors play a important
role in flying. The airfoil lifts the plane in the air, and once up, thrust will push the aircraft forward.
We need energy from an engine to create thrust. However, when we thrust something forward in
the air, the air pushes back, or resists, the plane. This resistant force is called drag. If or when
an airplane slows down, the weight, or gravity, and drag will take over. This will lower the
altitude of the place, which we use for landing.
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Airplanes/Jets
Let’s Test it Out!
First, we are going to quickly test how an airfoil
works! This is super easy. Cut a 1 inch slip from
a regular sheet of paper. Hold the end of the slip
under your bottom lip, and blow out with your lips
tight like hen whistling. What happens? Why do
you think this happened? Use the vocabulary we
learned on the last page to help explain.
Let’s make paper airplanes!
Now we get to the fun part! Using different types of paper, different sizes, and even some weights,
we re going to test the 4 forces (lift, gravity, thrust, and drag) to see how far we can fly a paper
airplane. I have some examples of patterns you can use below, but remember, you are not limited
by the size, look, or weight of your plane. Keep track of all the planes your make on the next page
and record how far each one travels. What do you think helped your plane fly longer? What held
it back? Use the vocabulary words we have learned today to describe each attempt.
Portrait
Landscape
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Paper Airplane Trials
Airplane Name
Unique Factor
Used
Distance (inches)
Type of force
tested (you can
use more than
one)
Sgt. Pepper
Added a weight
(penny) to the front
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Drag, Gravity
Vocabulary
Altitude: the height of an object or point in relation to sea level or ground level
Airfoil: a structure with a curved top designed to give the most lift to drag in flight, used as
the basic form of the wings
Ballonet: a separate gas- or air-filled compartment within the main envelope of a balloon
or airship
Buoyant: able or apt to stay afloat or rise to the top of a liquid or gas
Drag: the pulling force applied by air or other fluid surrounding a moving object.
Lift: an upward force that counteracts the force of gravity
Rudder: a flat piece, usually of wood, metal, or plastic, hinged vertically near the stern of a
boat or ship for steering
Thrust: the sudden force or push in a specified direction
Weight: the force exerted on the mass of a body by a gravitational field
Fill in the following sentences with the vocabulary words you just learned.
Use context clues to help:
Airships use ____________ to steer and____________ to
direct a negative or positive _____________, controlling
its height or ____________. Airplanes, on the other hand,
require the shape of the ___________. These wings use
lower air pressure above it to create ________. The
engine creates ____________, preventing ____________.
All this helps planes fly, regardless of their
______________.