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.
aeronautics_building

 

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.
aeronautics_testing

 

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.

 

 

Planning a Fun Science Fair in 10 Easy Steps

For the past few years, I have organized an informal science fair for our local homeschool community.  It has been such a joy to see the diversity of projects, listen to the kids share their experience, and receive encouragement from one another.  It takes little effort on my part to coordinate the event and I walk away reinvigorated and more enthusiastic than ever.  Today, I share a step-by-step guide to planning an informal and rewarding science fair.

This is the third year I have coordinated this event and the first time I’ve done so here in California.  It is always interesting to me to see how the participant numbers vary.  Regardless of how many students take part – 10 or 45 – it is wonderful opportunity. My children thoroughly enjoy the process and the chance to share their work with others.  I want to encourage you all to take part in a science fair yourself.  If you find your area lacks the opportunity, don’t be discouraged.  You can follow the ten steps here to planning a great science fair of your own.

10 Steps to Planning a Science Fair

1.  Reserve a space

If you aren’t already familiar with a space you can use for free, this could be the most time consuming part of the process.  There are many possibilities around you … be creative and don’t be afraid to ask around.  Possible locations you may consider include:

  • Fraternal lodge like Sons of Norway, IOOF, Lions, VFW Hall, etc.
  • City library
  • Church
  • A public school
  • Hotel conference rooms
  • A common house within a subdivision
  • A conference room at your spouse’s (or a friend’s) work

2.  Set a date

The date will likely be dictated to some extent by the calendar of the meeting space you select.  Keep in mind that science projects require planning time.  I like to plan the science fair sometime in the spring (late April or early May).  I announce the fair on our homeschool boards (Yahoo Groups, Facebook, and at local umbrella schools) in the fall, however, and provide regular reminders throughout the year.

3.  Make a flyer and registration form

With the logistical things out of the way, use a word processing program to create an attractive flyer and accompanying registration form.  Share these with your local homeschool community, including charter schools.  I charge $5 per family (or per participant), enough to cover the cost of the awards, but do what feels right to you.

4.  Determine award criteria and purchase awards

Perhaps you would like to invite a couple scientists to come a judge the student projects.  If so, you will likely want to use a simple scoring guide or rubric.  Alternatively, you may decide not to give out awards at all.  This is entirely up to you.  The fairs I have coordinated have been small, we have thereby had success with simply allowing the kids to vote for their favorite project.  The votes are tallied and prizes are awarded to the top three projects with the most votes.  You may also wish to have grade level distinctions depending on the size of your group.

5.  Get the word out and send reminders

As the date approaches, be sure to send out regular reminders and continue to distribute fliers or registration forms.  You may wish to hang a flier at the library.  You may also consider contacting the local newspaper to invite the public – and even a reporter or photographer – to the event.

6.  Create a program to identify participants

I would highly suggest having a deadline for registrations, perhaps one week prior to the event.  This should allow you time enough to create a program (a simple sheet of paper will do but you can get very creative) listing the participants and their project titles. Many families like to keep these as souvenirs or to take notes upon as the students give presentations.  I have found though that at least in my homeschool community, getting families to commit in advance is like pulling teeth.

7.  Create participation certificates or buttons

I have found the kids really like buttons.  If you have a Badge-a-Mint, I highly suggest you create a graphic image that you can print and thereby use for buttons.  You can even set up a station at the event so the kids can make their own.  Alternatively, you can print simple certificates.  Regardless, the kids appreciate the small token.

8.  Purchase small gifts for the winners

The award value is contingent upon the number of participating families.  This year, we had 3 families (not including my own) and 10 children taking part.  I thereby took in only $15 in registration fees. I thereby elected to award $10 for first place, $5 for second place, and $2 for third (yes – I covered a little out of pocket).  With larger number of participants – and with advance registrations – you can be more creative in awarding prizes. In the past, I have used the fees to purchase gift cards (Acorn Naturalists, Carolina Biological, etc.)

9.  Arrive early and greet families upon arrival

Let everyone know that the event is relaxed and informal.  Smile and be yourself. Depending upon the time of the day and the length of the program, you may wish to have snacks.  You can ask for family volunteers to bring something or if the participant pool is large enough, you can purchase a few things.

10.  Positive feedback and award the winners

Once everyone is set-up and as guests mingle, call everyone together and invite the participants to volunteer to share their projects.  If there are many participants, you may wish to divide into smaller groups (perhaps by grade level).   At the end, ask that the students vote for their favorite, tally the votes, and award the winners.

How to Plan Your Own Science & Art Show

I realized early in the year that our homeschool community was lacking a Science Fair so … I took it upon myself to organize one.  Knowing that not everyone would feel comfortable doing a traditional science fair project, particularly since a fair hadn’t been available for years, I thought a companion Art Show would entice additional participants.  I was so right!

It was relatively easy … and the impact was huge.  There was a tremendous number of participants and everyone was so enthusiastic.  I know there may be a need in other communities so I thought I would share here how I pulled it all together.

Planning a Homeschool Science Fair & Art Show

Step One

Essentially, I first reserved a space …  for me, the choice was easy, our Sons of Norway lodge.  During the work week, the lodge is used very little.  I thereby selected a date in April to allow much of the school year for work our our projects.  Though an evening would have been ideal for all parents and even extended family to attend, I wanted to keep the cost to a minimum.  It is my guess that finding a suitable location would be the most difficult step involved.  Here are some locations to consider in your area:

  • A local fraternal lodge like Sons of Norway, IOOF, Lions, VFW Hall, etc.
  • The city library
  • A church
  • A public school (non-profits are generally allowed use of the facilities after school hours)
  • Hotel conference rooms (I haven’t checked into this option, but it seems logical and they may even offer a discount – doesn’t hurt to ask)
  • A common house within a subdivision – though I believe one would have to be a member

Step Two

The next thing I did was inform the homeschool community of the date (determined by the reservation of the space).  This was easy … I simply posted it on our Yahoo board.  In doing so, I also asked for volunteers to help with the following areas:

  • Snacks (just a couple of moms to bring refreshments and snacks)
  • Greeter (someone to check in participants at the door upon arrival, and direct them to the appropriate table to display their work)
  • Prep & Clean-up (one – two parents to help set-up the tables just prior to the start and to help break down the tables and clean-up afterwards)

Step Three

I created a registration form and posted it on the Yahoo board.  The form included a statement of my vision (what I hoped we could achieve – essentially an opportunity to share our projects and thereby glean inspiration from one another), a statement of liability release (I didn’t want anyone liable for a damaged project or piece of art), and rules / regulations (limitations to project size, limitations on subject matter and/or objectionable content or materials).

For a $5 entry fee, each participant was allowed to enter up to three pieces of artwork (different media) and one science project.  The money was used to pay for the lodge rental, cover the cost of printing participation certificates, the prizes and the snacks.

Those who wished to participate were required to fill out the registration form and get it to me within 2 weeks of the event.  This allowed me time to print the certificates and purchase the awards.

Step Four

I set up an automatic reminder in the Yahoo system to encourage procrastinators to get their forms submitted.  In this way, the Science Fair & Art Show was at the forefront of everyone’s mind.  As the date of the show drew near, I called the parents who had volunteered to help and discussed any particulars (time to meet for set-up, reimbursement for snacks, etc.).

The Fine Points

To determine winners (1st – 3rd place), the students were given slips of paper and were asked to write down the name (or entry #) of their favorite projects.  Each child was allowed to vote once for a science project and once for an art project.  The votes were tallied and the project with the most votes received the prize for first place, a $20 gift card.  Second place received $10 and third place received $5.

I had originally planned for judges to interact with participants (particularly for the science projects) – to inquire about their scientific process, etc. but somehow or another, there was some miscommunication and the two judges I had previously spoken with failed to show.  Ah well.

Celebrate

The show was a spectacular success! There were so many participants and guests (many homeschool families and friends came to the event simply to observe) – that I determined two separate times (or days) would be necessary to alleviate crowding when we do it again next year.

In retrospect, I would also require participants to arrive an hour (or more) prior to the start of the show to set up their projects and for  judging to take place.  Though I didn’t intend for official judging for awards to take place – I wanted it to be low-key and relaxed – I thought some feedback from real scientists would have been beneficial.

Science & Art Fair 2011 :: Our Science Entry

Despite the fact that I was the one organizing the Science Fair and that science is my strong suit, we seldom found the time to sit down and do our science fair project.  Our original project was derailed due to weather and logistics (we wanted to do a maple syrup project … but we live in central Oregon and Sugar Maples (Acer saccharum), a species of maple native to the hardwood forests of northeastern North America, are hard to find.  This left us with little time to see a project through to completion.

Fortunately, I have a wealth of short projects that can be completed in approximately 45 minutes – one of the benefits of being a former science specialist.  I thereby described a project I used to do with my fifth grade students – goldfish gillbeats – and both kiddos were intrigued so we proceeded forth.  We gathered our materials – but rather than buy goldfish, we opted to use the two betta fish we already owned – and our experiment was underway.  Our goal was to answer the experimental question, “How does the temperature of the water affect the gill beats of a betta?”


Before we began, I asked each of the kids to write their hypothesis in their notebooks.  Meili stated that she expected the gills to beat faster in cold water because they would have to work harder to get the molecules moving and across their gills.  Buddy, on the other hand, hypothesized that cold water would slow down the number of gill beats because they would be hot and when you get hot you breathe more.

Materials:

2 betta fish
2 small glass jars
2 large glass bowls or jars
2 thermometers
1 pocket watch or timer
pencil and paper to record data 

Procedure & Setup:
Our set up involved placing each fish in a small glass jar with room temperature water (essentially the water from the fish bowl).  We recorded the temperature of the water and then counted the number of gill beats for 1 minute for each fish.  We counted again twice more to get an average number of gill beats.

We then carefully placed each small jar into a larger bowl of hot water (and later ice cold water), essentially creating something like a double-boiler system; though we weren’t heating the water – we just used hot tap water (and later cold tap water with ice cubes to bring the temperature down even more).  We recorded the temperature of the water and then counted the number of gill beats for 1 minute for each fish.  We counted again twice more to get an average number of gill beats.   These numbers were recorded in our notebooks for each fish.

[Admin Note:  In the classroom, when I have done this with a class of 30+ students, we have a significant population sample and can more easily compare/contrast experimental design flaws, etc. ]

Conclusion:
We discussed our results upon completion and were quite surprised by our numbers.  The two fish had significantly different gill beat rates.  Meili wrote, “After I was done with my experiment, I looked at my data.  My results showed that the gills beat the fastest in cold water, at about 77 beats per minute (bpm), an average of 66 bpm in hot water, and an average of 64 bpm in room temperature water.   My hypothesis was not correct though because the gills beat faster in hot water too.  They beat the slowest in room temperature water.  I think this is because they were stressed.”  We talked about how a larger number of fish to test would help to give us better results.  We also wondered if the species of fish would make a difference.
[Admin Note :: Due to procrastination … we were unable to type up our project and create a display board as we would have liked.  Our printer had somehow stopped talking with our computer – a glitch I wasn’t able to overcome – and we thereby had to print at the library at the last minute.  Even then … we forgot to include our data and to create a graph … producing a display that was sub-par.  Oh well … this allowed us to learn from our mistakes as well.  Another lesson learned.]

Building Toothpick Bridges .. a Lesson Plan

We have an opportunity this year to participate in our first homeschool science fair.  The kiddos have been fascinated with bridges for a long time so I knew immediately what project we’d undertake … Toothpick Bridges.  I’ll share with you my toothpick bridges lesson plan with you here.Buddy's Design

Capture Their Attention

Before we began construction, we read again the delightful picture book Bridges Are to Cross by Philemon Sturges.  We then used the internet to make observations of many modern bridge designs, particularly those we were familiar with here in Oregon as well as those we’d seen first hand in San Francisco.  I set up a little demonstration to show what structure was strongest … squares or triangles … using just drinking straws taped together at the corners to form a square and a triangle.

Strength in Design

I then gave the kids graph paper with which I instructed them how to begin designing bridges of their own.  They came up with several designs each – some of which weren’t feasible for toothpicks.  They then selected a design that would most easily be reproduced with toothpicks and we proceeded with construction.

toothpick bridge

Building Bridges with Toothpicks and Glue

In the classroom setting, I used to provide each team with a predetermined amount of money with which they would need to purchase their material … lumber (toothpicks) and welding material (school glue).  However, here at home, their imagination and thereby their design were the only limitations.

testing bridge strength

Testing Bridge Strength

We tested the strength of the bridges by suspending a gallon-sized milk jug beneath the bridge with a pencil.  Initially, we had used a smaller container but it turned out to be too small to contain the weights.  We then began to slowly add weights (marbles & metal washers) to the container.  When we ran out of weights, I began to slowly pour water into the jug.

toothpick bridge collapse

We continued in this way until the bridges finally collapsed or gave in to the pressure.  In the classroom, the eminent collapse and destruction of the bridges was always a highlight and was met with cheers and shouts of enthusiasm.  Here at home, I hadn’t anticipated the the big tears that we experienced.

toothpick bridge

In the end, the two bridge far surpassed our expectations.  Buddy’s design took on 16 pounds before it finally succumbed to the weight.  Sweetie’s design held more than 19 pounds!  Had she had more trusses along the roadway that supported the pencil, we hypothesis that her bridge could have supported more weight as her bridge remained intact with the exception of the road that gave way.

toothpick bridge

The kiddos are looking forward to presenting their experiment on Friday at the science fair.  Buddy is even talking about building more toothpick bridges – but he says he doesn’t want to test them.  “I don’t want to break my bridge.”

Engineering Marvels: Bridges

For more details and links to do this project with your kids, check out my Engineering Marvels: Bridges unit study.