## Aeronautics: How Airfoils Affect Flight

Like most young men, my son is fascinated by planes, trains, automobiles, and ships. His interest in each will ebb and flow like the tide, depending upon various things that give spark. Presently, he is focused on airplanes and would like nothing more than to fly one himself.

He insists that he is capable of flying a plane and enjoys proving this to anyone who will watch him as he plays a simulator game. I’m not so worried about the actual flying; it is the landing that gives me pause.

For our annual homeschool science fair, he expressed interest in designing different airfoils (cross sectional shape of a wing) for a glider to see how the different shape or camber (convex or concave curvature of an airfoil) would affect the flight distance.

### Research & Construction

A glider is a light, engineless aircraft designed to glide after being towed aloft or launched from a catapult.  It is composed of three main parts, the fuselage, wing, and the tail.

When air flows past the wing, due to the difference in curvature of its upper and lower parts lift is generated, which is responsible for balancing the weight of the plane, and the glider can thus fly.

Upon settling upon a style, he began designing and constructing his own glider out of a sheet of Styrofoam we purchased at Lowe’s.  For several weekends, he and his dad set about cutting, glueing, and sanding the foam sheets to resemble the fuselage. Along the way, a few modifications to his original design were necessary to enable the airfoils to be easily interchangeable.

### Testing: How Does the Airfoil Affect Flight?

Concerned that the glider would get damaged upon landing, he made the decision to launch it from a seated position.  He grasped the fuselage in the same spot and made every effort to be consistent with the effort he used to launch it each time.

A tape measure was laid out upon the ground and he measured the distance it flew (using the nose of the fuselage as the reference point). He flew the glider three times with each airfoil, recording the distances flown in his journal.

### Results

He discovered that there was no significant difference between the airfoils he had used; the average distance that each airfoil flew varied by only a couple of centimeters. He surmised that this was due in part to his low launch height, the design of the glider (would it have been better to have a slot in the fuselage so that the airfoil was lower?), and the similarity of the camber (perhaps the airfoils were not different enough; it was difficult to sand the thin Styrofoam without breaking it).

He was very disappointed but understood (after a few tears and much consolation) that his project did not fail.  Regardless of the result, he had a great time, bonded with his dad, and loved telling his friends about his project at the science fair.

## Science Milestones: Pioneers of Flight

Interest in aviation (design, development, production, operation and flight of heavier-than-air machines) can be traced back as far as Leonardo da Vinci. However, real progress toward achieving flight in heavier-than-air machines only began in the middle of the 19th century. Follow in the footsteps of the pioneers of flight, Leonardo da Vinci and the Wright Brothers, with fun hands-on activities exploring aerodynamics.

“Its a dream of every human to fly and reach the sky; either in terms of glory or literally. This aspiration to be in the wind and above all gives thrill and when you cant do so, you resort to objects and make them fly.”

## Leonardo da Vinci

### Biography

Leonardo da Vinci, whose intellectual range and capacity for action have been equalled by few, was born in Tuscany on April 15, 1452.  He is best remembered as the painter of the Mona Lisa (c. 1503) and The Last Supper (c. 1495). He is equally famous for his astonishing talents in architecture, sculpture, music, engineering, geology, hydraulics and the military arts, all with success, and in his spare time doodled sketches for working parachutes and flying machines like helicopters that resembled inventions of the 19th and 20th centuries.

He made detailed drawings of human anatomy which are still highly regarded today. Leonardo, cleverly, wrote notebook entries in mirror script, a trick which kept many of his observations from being widely known until decades after his death.

Though credit for the invention of the first practical parachute usually goes to Sebastien Lenormand in 1783, Leonardo da Vinci actually conceived the parachute idea a few hundred years earlier. His design consists of sealed linen cloth held open by a pyramid of wooden poles, about seven metres long. The original design was scribbled by da Vinci in a notebook in 1483.

“If a man have a tent made of linen of which the apertures (openings) have all been stopped up, and it be twelve braccia (about 23 feet) across and twelve in depth, he will be able to throw himself down from any great height without suffering any injury.”

Like many of da Vinci’s ideas, the invention was never actually built or tested by Leonardo himself. But, in 2000, daredevil Adrian Nichols constructed a prototype based on da Vinci’s design and tested it. Despite skepticism from experts, da Vinci’s design worked as intended and Nichols even noted that it had a smoother ride than the modern parachute.

### Bring it Home – Experiments with Parachutes

• Get a stopwatch and time how long it takes for an object to fall with and without a parachute. Do several drops and see if the time is always the same or if it varies somewhat.
• Using the same object, compare the results with a small and a large parachute.
• Using the same size parachute, compare results using two or more different objects.
• Try lengthening or shortening the length of the suspension lines. Try changing the number of suspension lines.
• Try different shapes for your parachute (round, oval, rectangular, square, etc.) and different fabric materials.
• See Science Projects with Toy Parachutes for more information
• Leonardo da Vinci’s Parachute Design – Power Point Presentation
• If you want to explore da Vinci in more depth, you’ll love Joan’s A Birthday Celebration: Leonardo da Vinci, art and invention at Unschool Rules.

## Wilbur Wright

### Biography

The Wright brothers were two of seven children born to Milton Wright and Susan Catherine Koerner. Wilbur Wright was born near Millville, Indiana on April 16, 1867 and his brother Orville on August 19, 1871. Together, they are credited with inventing and building the world’s first successful airplane and making the first controlled, powered and sustained heavier-than-air human flight, on December 17, 1903.  But they didn’t start off with airplanes. The American brothers decided in 1899 to master gliding before attempting powered flight.

First, the Wrights built and flew several kites, testing and perfecting their new ideas about a flight control system. In 1900, they used this system on a man-carrying glider for the first time. Before they risked their own necks, they flew the glider as a kite, controlling it from the ground. They flew three biplane (has two wings, one above the other) gliders from the sand-hills near Kitty Hawk, North Carolina, and by 1902 had developed a fully practical biplane glider.

Their great innovation was that their glider could be  balanced and controlled in every direction, by combining the actions of warping (twisting) the wings and turning the rudder for lateral control, and by using a device called an elevator for up and down movements without any need for the pilot to swing his torso and legs in order to control the flight direction. All flight control today has been developed from this 1902 Wright glider.

### Bring it Home ~ Experiments with Kites & Gliders

Visit my Science Milestones page to learn more about scientists whose discoveries and advancements have made a significant difference in our lives or who have advanced our understanding of the world around us.

To find out about more people born in April hop on over to iHomeschool Network’s April birthdays page.

## Little Boys with Big Ideas

Any parent with little boys can attest to their fascination with all things related to transportation. My little man is no different. He has been drawn to planes, trains, ships, and automobiles since he was a toddler.  As he has grown older, his focus has evolved to include aerodynamics, electrical circuits, and of course, magnetic levitation (you can imagine his exuberance in Shanghai when he got to ride on the Maglev).  A little boy’s imagination knows no bounds.

When something appeals to him, he latches on and with every waking moment is consumed with researching, role-playing, drawing sketches, and telling anyone willing to listen, all the facts he has learned.  To be honest, his obsessions are a little overwhelming for he tells you the same facts over and over, jumping from one airplane to the next, rattling off the specific airline make and model along with the engine size and maximum speed …  “We rode on a Boeing 747-400, United Airlines flight #889.  Each of the four engines has a maximum thrust of 63,300 pounds. It has a cruise speed of 565 mph and an altitude of 41,000 feet. It can carry about 400 passengers.”

## Little Boys’ Imaginations

This past week, he has been obsessed with airplanes.  His dad has a small collection of RC planes in our garage – his hangar if you will.  He used to fly them when the kids were toddlers but he’s developed other interests.  He had considered selling them – and did sell a few – but I encouraged him to keep a few knowing that when Buddy got older, it would be a hobby they could enjoy together.  That time has come.

He spent hours ogling one of the planes; running with it in his hands down the street in front of our house, feeling the wind ride over the airfoil and how it affected the lift. He then sat down and began to craft a plane of his own using a cardboard pizza box, electrical tape, Lego wheels, paint, a hot glue gun, and his Snap Circuits set.  I was mighty impressed with his ingenuity and raved about his design.  He was heart broken that it wouldn’t fly on its own.  He laments that he spent so much time on it and it didn’t work. I encouraged him to not give up, “Don’t be frustrated.  Each time you try, you learn.  Your design improves and you do better the next time.”  It is a hard lesson.  One I could never teach with any curriculum.  This one he needs to learn on his own.

He has never been a big reader of books – he is too active to sit still long enough to read more than a chapter at a time.  Yet he devourers audio books.  With each new story, he acts out his favorite scenes and really gets into play-acting, quoting passages and bringing the characters to life.  That reminds me – I really need to find a drama class for him.

Upon watching the new BBC program, Merlin, he has become intrigued by King Arthur and his knights.  While traveling in China, he carried along the Classic Starts edition of Howard Pyle’s “King Arthur and His Knights”.   He didn’t read much of it – but he was on a quest to find the perfect medieval sword at the tourist shops.  The sword he ended up purchasing featured dragons and Chinese characters so upon our return home, he was insistent that he still needed a proper knights sword.

This past weekend, we drove up to see family and he was delighted to spend the entire day in the basement with Papa crafting a sword that he would be able to use in real sword play (it is made of wood).  He is also in the process of making his own chain mail.  He came across a wonderful tutorial on YouTube that utilizes soda pop can tabs.  We don’t buy soda (or beer for that matter), so it will take us a while to collect enough tabs to complete his costume.  With the help of Facebook and FreeCycle, we hope to finish in time for Halloween.

I love his passion, imagination, and excitement.  I didn’t actually realize his figures were accurate until I looked them up while writing this post.  Now, I sit here impressed and a little mystified as to where this child came from.  Somehow, his little piles of cardboard scraps and aluminum foil, electrical wires, and duct tape don’t see so frustrating anymore.  I am blessed.

## Discover Aerodynamics with Simple Kites

As we expand upon the vision of our Roots & Shoots club, we have begun to incorporate more involvement from the other parents … something I am very excited about.  Upon request of the kids, one of the first themes we have begun to explore is Aerodynamics & Flight.

We began with simple kites last week and each parent brought an activity or snack to share.  I read aloud a brief history of kites and touched upon the prevalence of kites in Asian and Middle-Eastern cultures.  We then began construction.

We had several simple kites to choose from but opted to begin with one made from a single sheet of 8 1/2″ x 11″ paper.  This style also required a small wooden dowel or straw for strength (you can see in the picture above the kids cutting the dowel to size) as well as holes cut in the wing tips for the string.  This wiki-page gives detailed instructions, How to Make a Fast Kite with One Sheet of Paper.

At one point, the hole punch got jammed with paper so I attempted to dislodge it and accidentally sliced the tip of my thumb with the scissors.  Dumb mistake.  Justin – our awesome homeschool dad – came to my rescue, applying pressure to stop the bleeding while my little buddy found the band-aids.  My blunder provided an impromptu lesson in first-aide!

The second kite we made were Asian-inspired carp kites made from tissue paper (Koinobori). To make the koinobori, we simply folded a piece of tissue paper in half. Students drew the carp shape, making sure the fin was opposite of the fold. They then cut it out, opened it up, and drew the other half of the carp as symmetrical as possible. They were encouraged to color it with oil pastels.  Pipe cleaners was adhered along the mouth with tacky glue. Glue was also used to glue the rest of the fish together.  The mouth was kept open by bending the pipe cleaners. They then used a hole punch to punch a hole in the center of the mouth to attach the string. Upon completion of the kites … they kiddos were anxious to get outside and fly them.  Unfortunately, the weather didn’t cooperate and there was little wind.

We had such a good time – we didn’t get a chance to make all the kites we had planned for.  We will thereby revisit kites again next week.  Our vision is to then explore ‘lighter than air’ (hot air balloons), airplanes and eventually rockets.   I can’t wait to share all that we have planned … the field trips and special guests.