Whirly Birds - A study in Hydrodynamics and Biomimetics

I know. It's a mouthful, isn't it? But this is a great project.

I've been doing it for a long time, and every time, the students love it, whether they are in 2nd grade or 6th grade.

This is what we're making today.

An important disclaimer first. I got this project idea from science buddies.

Please check out www.sciencebuddies.com. It's a great place for project ideas.

Before I start the project, I discussed the concept of biomimicry. Simply, it means that engineers are trying to use what we find in nature to improve functions of man-made objects. A splendid example is velcro. It was invented by a man who went for a walk with his dog and came home with a lot of hooked burs from the local hills on his socks and his dog. He studied the burs and invented velcro. Imagine that!

Cat's Paws and Catapults by Steven Vogel has a book full of Biomimetics examples. You might want to check it out.

So, what is biomimetics?

Studying and Learning from Nature

One of the best examples of Biomimetics is velcro. A Swiss engineer took his dog for a walk and found these things clinging to his dog's belly and legs. It took a long time for him to take these things off, and one day, he looked closely at the things he was taking off his dog. He found these tiny hooks at the end of the things that were clinging to the stomach and eventually invented velcro. Can you believe it?

Sciencebuddies.org used to have a wonderful lesson associated with this, but it's no longer available (at least I couldn't find it). So, I'll have to do my best to give you a short summary.

The bumps on humpback whales' fins called tubercles (scalloped pattern)

help the whales swim through the water easily.

The spikes on sharks' skin called denticles (saw-tooth pattern)

help the sharks slice through the water effortlessly.

Scientists and engineers are working to incorporate these design elements to planes and ships, among other things. They believe that if we could put a thin skin of these patterns on our planes, it might cut our travel time over 50%!

Imagine that!

For this project, you need to cut out the three separate patterns, test them and figure out which pattern helps the whirly-bird slice through the air best.

When I do this project in class, I'm the client and the students are aerospace engineers who are competing in teams to win a chance to build a revolutionary new aircraft. They must test the three patterns and make recommendations according to their flight data (how long the various whirly-birds took to reach the ground).

List of Supplies:

• Paper, to copy the whirly bird designs on them.

I've used different kinds of paper in class (plain copy paper, construction paper and cardstock paper), and it really doesn't matter what kind of paper, as long as they are different. I want the students to notice the difference in flight.

• Scissors
• Craft scissors for make patterns.

It would be nice to have scalloped and saw-tooth patterns, but this is not a must have. Any sharp vs. curvy pattern would do.

• Pencil and notebook paper to take down data.

I have the students count in their own consistent way to keep track of how long it takes for the whirly-birds to reach ground.

Build instructions:

• Cut along the outside solid lines.
• Cut the side lines (about midway down) and the blade lines.

If you have craft scissors, use them to make the cuts. If you don't have the craft scissors, make the cuts like the patterns, but you don’t have to follow the pattern exactly. As long as you get a saw-tooth pattern (sharp and pointy) and a scallop pattern (rounded and wavy), they should work.

• Fold length-wise, along the bottom half of the whirly-birds

• Fold the sides in.
• Fold the blades out in opposite direction.

• Hold it out in arm's length and release gently.

Don't try to throw it. The best results come from gently letting it go in the air.

And how fast it reaches the ground is important, but what's more important is how smoothly the blades slice through the air as it descends to the ground.

Basic Design

After students have tested the three basic designs, I ask them to make designs of their own. There are no restrictions here except that the students CANNOT leave their whirly-birds in their original design.

I was hoping to attach a link to this pattern from sciencebudies.org, but this pattern is no longer available, but the patterns look like this.

Again, rounded, scalloped pattern represents the whale tubercles, and the saw-tooth pattern represents the shark denticles. The straight line represents the standard blade-edge design for helicopters, wind turbines, etc.

When I do this project in a classroom, kids line up 3 to 4 in the front of the classroom. Then they release their best whirly-birds at the same time, and the teacher and I judge according to the smoothness of the flight and how fast it descends to the ground.

Please note that the fastest whirly-bird isn't always the winner. We look at the smoothness and the beauty of the flight more.

Other things to look for in judging Whirly-Bird Olympics:

• Flight patterns
• Swirls
• Turn speed
• Creative Blade design

Have fun!

Hoop Gliders

I came across these hoop gliders several years ago, but I revisited them with my children when we were participating in the Tech Challenge 2016, Taking Flight. And just like the Birds of PLAY, we made these gliders to prototype (we thought using the gliders in the shape of birds would be fun at the competition) and understand the mechanics of flight.

Before you start, throw a plain straw. Does it fly well? Not really. It’s because the straw doesn’t have wings. It has nothing to generate lift. But when you add hoops, they act as wings, generating lift. And depending on where you put the hoops, your hoop glider will generate more lift or less. You experiment with sizes and locations of the hoops and decide what works best for your hoop glider. 

 This is what we're making today. 

These are quite simple to make, and they are incredibly fun to throw and watch them fly. This is a great project you can do with your children/students inexpensively. I hope you try this project and have a lot of fun.

List of Supplies:

·                     Straws (different lengths and diameters)

·                     Paper strips (copy paper, construction paper, cardstock, etc., whatever you have handy)

·                     Scissors

·                     Adhesive tape

Cut the paper in 1/2" or 3/4" strips. You can experiment with other widths, but these are the widths that seemed to work best. I also have three different sizes of straws. For my convenience, I made my hoop gliders with the wider, pearl drink straws. But I had students make hoop gliders with regular straws, and they did well with the smaller diameters, too. So, it really doesn't matter too much. Again, if you have different sizes available, experiment.

These paper strips are 3/4" wide. I like this width for no other reason than that it's the width of scotch tape. So, that's the width I use, but I've seen other project instructions online with 1/2" width instructions. Tape the ends of the strips together and make circles. You can experiment with lengths, but I tend to use 3", 6", 9" and 12" strips. I don't know why. I think it's the proportions that matter, not the actual lengths.

You can put as many or as few hoops as you want. But the minimum number is 2.

Have fun with where you put the hoops. Go crazy and fail spectacularly!

As you see, the left hoop gliders hoops are not aligned. The hoop in the back is attached in the middle, but the hoop in the front is attached to the right handside. Play with where you attach the hoops - in the middle, left side, right side, etc.

Just want to show you the different sizes of the hoops I attached. Again, the goal of these projects is to have fun.

I made 4 hoop gliders this morning. but when I conducted this project in class, some students have made as many as 10+ gliders. So, make a lot and have fun.

How to throw a hoop glider. Gently throw it forward.

 

This one flew pretty straight and far.

This one flew the farthest, almost toward the fence & the rose bushes.

This one was interesting to look at slow-mo, because the largest loop would swing back and forth between left and right. But it didn't fly far.

This one was all over the place, but interesting to watch.

It's a perfect day to fly gliders! Have fun!

Squeeze Bottle Rockets

This is a variation on Strawkets I saw at RAFT, and I wanted to see if these would fly as well as the original Strawkets experiment I did with students a while back.

Four 6th grader classes conducted this experiment recently, and the results were conclusive - lung power wins! There's no comparison between lung power and squeeze bottle power. Unfortunately, I didn't take pictures in class, so I took these pictures separately.

This is what we're building today.

List of Supplies:

• Straws, 2 kinds, one skinnier than the other (they should be able to slide easily inside of one another but not too loose)
• Facial tissue
• Index cards
• Adhesive tape
• Scissors
• Squeeze bottle
• A piece of soft foam to cover the bottle opening

All the materials are easy to find except for the squeeze bottle. I think you can find these at Target or Walmart in the travel container section.

The black piece on top of the squeeze bottle is a squishy foam with a hole in the middle for the straw. If you don't have anything like this, you can just tape over the opening, insert the straw, and tape around the straw to make sure that no air is escaping (except through the straw).

Try flying your straw rockets with the inner straw pushed all the way in & pulled out to the bendy neck of the skinnier straw. Experiment and find out which way works better.

Take a piece of tissue, twist and fold into an oval shape, and push it into one end of the straw to make it the front end of rocket. Cut pieces of an index card (try to have fun with different shapes and sizes) and attach them at the end of your rocket as tails.

These are some of the shapes I experimented with today, but in class, students are VERY creative with sizes (huge to tiny) and shapes (let your creativity explode). Have fun with them.

This is one of those experiments where I have the students yell, "Fail Spectacularly!"

So, go forth and fail spectacularly by experimenting with crazy shapes and sizes.

And always, I hope you have a lot of fun.