Aerodynamics of Boomerangs

I promised this a long time ago but I was too busy to write up the details and there were a couple of things that I needed to figure out how to explain better. I think I can explain how a boomerang works to absolutely anyone. That being said I may be wrong so if there is something that you don't understand in my explanation just ask.

We'll end up talking about a lot of stuff that doesn't have to do with boomerangs just so that we have all the details we need. In fact, we'll start by talking about syringes.

So you go to a doctor and they give you a needle. The fluid in the main barrel is flowing with some speed because the nurse is pushing on the end but when it gets to the needle part what happens? Because the area of the pipe has changed the fluid must move faster to get the same amount out in the same amount of time. Maybe the diagram helps a bit.

OK. Now let's talk about something seemingly completely different (and still with nothing to do with boomerangs). You're driving really fast on a highway in your Batmobile. Then you pass a semi-truck (driven by the Joker, maybe?) that is going the other way. What happens? You get sucked TOWARDS the truck not blown away from it. How come?

This has to do with Bernoulli's equation (I swear this is the only equation that we will need in order to understand boomerangs so don't get scared away, dear reader) which says that pressure plus velocity (squared) must stay constant. That means that if velocity is increased the pressure must go down and if velocity is decreased the pressure must increase to compensate and make sure that when you add them together they stay constant.

So what happened with the semi-truck? The truck and you form a short channel and just like the medicine in the syringe speeds up in the needle, as air passes between you and the truck it must speed-up too. BUT if the air speeds up that means that the pressure must go down between you and the truck (Bernoulli's equation) but the pressure on the other side of your car stays the same. That means that there is a stronger force on the other side pushing you towards the truck.

Good. Now lets talk about airplanes. Airplanes are like boomerangs, right? Forget about everything except the wing. The wing of an airplane is an aerofoil. The air that passes on the top of the wing is pushed up and has a longer path than the air below. So the air above goes faster than the air below. That means (by Bernoulli's equation) that the pressure below the wing is bigger - there is a force pushing up on the wing! This is the lift force and it's what makes airplanes fly.





Now it's time to use our imaginations. Imagine turning a wing complete sideways . Now what happens? Well for one thing there is no force counteracting gravity and it will fall but there is a force pushing it sideways. The side ways force will make the wing go forwards and sideways. It will curve but it won't quite go turn and travel in a circular path just like a boomerang.

BUT this has a bigger problem. What? Well think of a pencil that you balance on it's tip - and you laugh at me and say, "how could I balance a pencil on it's tip. The smallest bump imaginable would cause it to fall over." Right! As it tips gravity can enact more and more torque on it since as it tips the centre of gravity moves further and further away from straight over the fulcrum (like where the pencil is touching the table).

Our imaginary turning wing is even worse. If it started to tip (as it definitely will) then not only would gravity make it tip faster and faster but also soon the lift would be pointing down more and more. Our sideways wing will flip over really fast and as soon as that happens it's not going to move in a circle anymore. It will just crash downwards. Maybe the series of diagrams illustrates it.

Here's an idea. A pencil will tip because it's unstable but what if you spin the pencil really fast? Now it's like a top. As long as a top is spinning fast enough it will be stable which has to do with angular momentum. Even though gravity pulls down on the centre of mass as it starts to tip, it doesn't fall because the angular momentum which points up from the tops principle axis changes the direction of motion and causes it to have processional motion rather than falling.

So let's spin our wing. The spinning will cause the wing to be staple and it will move in a strafing path rather than tipping.

Good try but there is another problem! The wing is travelling one way at the top of the circle and the other way at the bottom! That means at the bottom the aerofoil is facing the wrong way. How do we fix this? Cut it in half and turn one arm around and glue it back together. That way the aerofoil is pointing the right way at both the top and the bottom. This is a boomerang! The wing on the top and the wing on the bottom both have a lift force pointing in the same direction causing the boomerang to turn to the left (that's why boomerangs can only be left or right handed - they have to be built differently for different hands). The two diagram shows how the aerofoil shape has the leading edge on opposite sides of each each arm of the boomerang.

The wing on top is traveling through the air faster than the bottom one because the boomerang is spinning and moving forward and the top wing moves with it while the bottom wing moves against the direction of motion. So the forward moving top wing has more sideways force than the retreating bottom wing. This unequal force is what turns the boomerang so that it goes in a circular path and not just side ways. The turning force comes from the unequal air speed of the spinning wings while the spinning is able to keep it steady.

The bend in a boomerang isn't needed at all although I've read that it makes it easier to throw. That's what I know about boomerangs.

If this was too long an explanation then you should check out

avkids
Boomerang Shop

If this was too short and you were saying to yourself, "It doesn't mean anything if it's not expressed mathematically" then the websites for you would be

Unspinning the Boomerang
Boomerangs.com

And if you still aren't satisfied check out this really in depth look at

Research Support Technologies

Batarang Found

I went out one last time to try to find the boomerang that I lost. The wind had blown all weekend and most of the leaves are off the trees now. I'd gone looking 3 or 4 times during lunch hours and on my way home from work and I was starting to feel like I would never find it again.

But I did! There it was hanging from a branch in this little tree in someones back yard. I could just see it over the fence.

It's a little beat up (I think the rain warped it a touch) but it flies just fine. Now I just have to hope that it doesn't snow tomorrow.

Poison Ivy Ate My Batarang

I still haven't found my boomerang. I went out a couple of times over the weekend but I can't find it anywhere. I check the ground I've been looking up in the trees but I just don't see it. There are a couple of big evergreens in the area so if it's stuck up in one of those, I don't know if I'll ever get it back.

In the mean time, I've ordered two new boomerangs. I feel confident enough with how well things had been going (before a tree ate my boomerang) that I bought two intermediate level ones: the Rainier and the Adirondack Standard. I got them both from the Boomerang Man again.

Hopefully, I they arrive before it starts to snow.

Poor Batman

When my day was done, I took my boomerang to a football field to practice throwing some more. I had a rough time at first. In fact, my first couple of throws duffed right into the ground - which by the way is pretty impressive because the boomerang hits hard and bounces up but then since its really a flying gyroscope it stabilizes itself and flies really far. Those seem like especially dangerous throws since the boomerang stays so very low to the ground and its definitely definitely out of control.

Anyway, eventually things got better and I made some pretty good throws despite the wind. I was even throwing it around the goal posts so that it went past the posts, circled around them and came back to me. But as it got darker it also got gustier. One throw which started out looking pretty good the ended up being my last.

The boomerang started to climb really fast all of a sudden and the stadium lights which had been great up until then made me lose sight of its flight. Since the boomerang started climbing, it wasn't turning as sharp anymore. I had been getting a feel for the way boomerangs fly so I knew the boomerang would be WAY to my left.

I couldn't see it, but I could definitely hear it when it crashed into the tree tops. It had flown right out of the football field. I peered though the field's netting but couldn't see it any where so I climbed the fence and searched the grove of trees for a long time. I never found it.

"Batman and Robin Will Never Die"

I haven't posted in a while. I guess that's what happens when you aren't independently wealthy with billions of dollars to spend on becoming the Batman. But although I haven't posted I've been doing plenty of practicing. I'm not a pro but I am definitely getting better with the boomerang. I can make it return to me within a circle of radius say 5ish yards consistently now as long as there is very little wind. But man the ol' batarang is starting to look pretty beat up from all the fences, poles, bleachers, sidewalks and people I've hit ... ok so I haven't hit any people yet.

Hopefully this weekend I'll be able to write a post about how to throw a boomerang and what the science behind boomerangs is. I thought I'd write that last one because the other day when I was walking back from the football field carrying my boomerang, I overheard a couple of guys talking about how they "didn't believe in boomerangs". There's all kinds of people in the world. I wonder what they do believe in.

I've also been practicing writing and drawing with my left hand. Maybe I'll scan some practice sheets to show you.

And finally I met a girl today who fences! Hopefully I'll be able to convince her to give me some lessons because I'm a firm believer that Batman could duel Zorro to a stand still.

Building Batman - Boomerang: Day 3

I went out to practice with my boomerang again and things started out really well. I decided to try a new park - one more on my daily path. Its smaller with more trees and all-n-all a bit nicer than the one I had been going to. To test the wind and the size of the park my first throw was pretty light hearted. My throw curved but definitely didn't come back. My second throw was a lot more serious though. I chucked it low and hard. It came back perfectly - my second throw of the day and it was great. The next three throws were nearly perfect - the boomerang started low and straight, turned and climbed then came right back to me. It was great. On my fourth throw, I got the boomerang stuck in a tree - a big tree.

Fact: When throwing a boomerang you really, really... really really need as much space as they say you need. If your boomerang goes into the foliage of a tree, you are royally screwed. It is a light bent object and so it will not come down.

I felt like a little kid looking way up there and knowing that I would never be able to have my toy again. But I decided I would try to get it back. The branches were too a few feet too high to reach and the trunk too wide to shimmy so I tipped over a nearby garbage can and climbed up that for some added height. It still wasn't enough to reach a branch so that I could start climbing.

I tossed a stick up into the leaves a bunch but I never hit it and did alot of staring up, trying to look like I was formulating a plan and not just praying that a gust of wind would magically come by and blow it out of the branches.

Luckily, some people playing football in the park had been impressed enough with my initial throws (or just the fact that someone was actually trying to throwing a boomerang) to start a conversation with me. They now came over and after a couple of tries and some sharp eyes, they had knocked the boomerang back down to earth.

At that point, I went home. I'll try again tomorrow.

Boomerangs

Boomerangs!!! I received my boomerang in the mail today. OH MAN! It is so great. I came home, the package was waiting for me and it was a perfect day to be outside. So I dropped my stuff and ran out to a pitch.

I was worried to start throwing because I had read this blog and I was pretty sure that I wouldn't be able to get it to turn around but I had read alot of instructions on the internet (like this one, this one and this one) and the instructions that came with the boomerang (which is from the Boomerang Man website, if you forgoit) said exactly the same things.

My first throw turned a bit to the left (that's the direction that right handed boomerangs turn)s but definately didn't come back. I figured it needed to go higher to make it all the way around so I tilted it more - the boomerang shot straight up into the air, crashed down and bounced a couple of times before it died. But it wasn't broken so I kept throwing and throwing

and throwing




and throwing











and throwing until I caught it! It was far from perfect. I had to run to catch it but: I threw the boomerang, I watched the boomerang turn and I caught the boomerang! They say that that the best way to catch a boomerang is with both hands, clapping down on it like a crocodile's jaw but I think I only caught it once like that. I found it much easier to catch with one hand. That is probably the boomerang. The one that I picked is a beginner model and so when it is thrown well it hovers over my head for a second before I catch it. I think that with practice I will be able to throw it lower and closer to the ground but for now I'm just happy when I can catch it at all. After my first time, I was able to catch three more throws (and screw up a hundred) before it got dark. I'll go back out to practice more tomorrow morning.

PS I thought about boomerangs being a weapon: a boomerang could definitely be a weapon. If the boomerang hit anything on the first half of its trip it could cause some serious (although probably non-lethal) damage but the beauty is by the time it has finished its return, the boomerang has slowed to a manageable speed. I take back what I said about a real life Batman not actually using a boomerang. In actuality, using one that turned really tight, with enough practice and skill a boomerang would be perfect for the Batman. That being said I'd love to see anybody throw a boomerang while wearing leather gloves or catch a boomerang thrown in the dark or a narrow alley.

Picking the Perfect Boomerang

Chances are pretty good that the city you live in doesn't have a local shop that sells boomerangs(mine doesn't). So that means that if you are going to buy boomerangs, you'll have to do it online. Maybe my thoughts on distributors will make things easier for you.

Kendell's Boomerangs

Good page. Well laid out so that everything is easy to find with a fairly good description of each boomerang. Orders are emailed or by mail.
Beginner: The bottom three boomerangs(Correla,Flared Vee and Beta) look like the kind of thing that you might be interested in. At $12 each they are a great price.
Sport: The most expensive sport boomerang is only $25. The Ultra V and the Ohm look like particularily nice traditional shaped boomerangs.
Shipping:
USA $6 Shipping/handling for orders of $10-70 or $8 for $70-100
CANADA $20 Shipping/handling for orders of $20-50
INTERNATIONAL $25 Shipping/handling for orders of $20-50
If you check out the artistic section, Batman-fans might just be in for a surprise.

Boomerang Man

There are lots of boomerangs on this site! Unfortunately, it looks like it hasn't been organized in a while - there are beginner boomerangs in the intermediate section and intermediate ones in the beginner. I guess its not a clean cut devision but... The thing to notice is this website doesn't make their own. Accepts PayPal and phone orders.
The Yanaki looks like an especially good beginner boomerang. I'd be willing to spend a little more money for a boomerang that will last as long as it sounds like this one will. The Glacier also sounds good since it doesn't need to be thrown very hard.
For more intermediate boomerangs check out these guys: The Rainer looks like a good one because it flies low. That appeals to me. MAN! So many good sounding boomerangs! I don't know what to say about them all - The Raptor, the Adirondack Standard, the Eagle... Wow these are all Colorado boomerangs. BUT STRANGELY ENOUGH THEY ARE ALL CHEAPER THAN ON THE COLORADOBOOMERANGS SITE!
Shipping: $6.00 Shipping/handling on USA/CANADA orders of $49

Colorado Boomerangs

Use this site together with the BOOMERANG MAN - you'll be better informed and maybe you'll save a couple of dollars. Most of the BOOMERANG MAN's boomerangs come from here and are often cheaper but reading a second write-up is really useful in deciding which boomerang to get.
Shipping: $4.95 Shipping/handeling on Continental USA orders under 4lbs. ($12.95 Canada and 19.95 Europe)

Wallaby Boomerangs

Don't let the fact this is the nicest website of the bunch fool you. There really isn't alot of selection and the prices seem comparatively high. It doesn't really matter which region you chose - the selection is always the same. I think the easiest way to see what they offer is to go under the online boutique and chose catalog.
The catalog doesn't have much information really and like I said there are only a dozen to chose from and they seem about $10 too expensive. Is exotic wood really that important?
Shipping: They don't tell you the shipping until you've already started filling in VISA info - $9

Cryderman

As I always say, any boomerangs good enough for Prince Charles are good enough for Batman. That's right, the royal family owns a pair of Cyderman boomerangs. These are expensive boomerangs but man, are they gorgeous. The wood is all inlayed and sexy. My only real problem is that there is no information about how each one behaves. I don't really think that these are beginner boomerangs.

BlueStarRangs

This is a good site. Apparently, the "G 12 rangs are unbreakable". If you go to the very bottom of the Products page there is a sports link. This shows a bunch of sets of boomerangs. The first set {VeeRang, Trapezoid, Falcon} seems like the perfect group. If you want to get a more than one beginner boomerang maybe this set of three is a good recommendation
Shipping: 12euro Shipping/handling on European orders of 3-5 boomerangs. $21 Shipping/handling on USA/world orders of 3-5 boomerangs.

DGM Boomerangs

These boomerangs are $50 a pop. They really do look great - when this guy says they are painted by hand he means hand painted not spray painted. I can't say for sure but once I see how much I enjoy throwing and have gotten good with some different beginner models, I may buy the KAMIKAZE. Its return flight is low and quick, they say it whips in rather than hovers. That sounds great if you are good enough to make it work.
DGM BOOMERANGS' shipping/handling fees are all over the place and seem high. Check it out for yourself.
And for those of you who are real Batman fans, the ornamental batarang just might be a must-have.

boomerangs.com

I like how friendly this site is. Since it is organized by brand, price checking is easy (with the exception of Samba Boomerangs which I didn't find online anywhere). That being said, it does seem like the WalMart of boomerang sellers. The prices are comparable - sometimes higher than the Boomerang Man by a couple of bucks, other times a touch lower.
Shipping/handling is reasonable at $4.95 for Continental U.S. and $16.00 international (Canada, Mexico, and Europe).

REDI Boomerangs

These boomerangs LOOK fine but the writeups about how they fly are not super informative and at 18euro or higher plus a complex shipping scheme, I'm just not interested in taking the risk. Plus, it doesn't look like they ven ship to the new US.

So in conclusion, it seems that the selection of beginner boomerangs, price and shipping of the Boomerang Man is best, although you might want use the site with Colorado Boomerangs. I'm going to order 1 single boomerang to begin with. And my choice is (drumroll please) the Yanaki. Durable, accurate, handles winds well, really nice to catch, excellent first timer. cannot and will not go wrong - do I really have a choice? It sounds like this cheap boomerang is perfect for a beginner like me.

I can't wait to give it a whirl. (Oh man, I hope they don't ban me from the internet forever for making such a terrible pun)

Batarang

Batman needs his Batarang. If I had to name two tools that every incarnation of Batman has, I would pick his Batbelt and his batarang (this UGO article agrees, too).


So I've started shopping for a boomerang. I couldn't find a local shop which kept them in stock but there are plenty of good places on the web to buy them. As always I know nothing about this Batman skill so where's the best place to start looking? Wikipedia. From there, I happened to find Canboom which made me realize that most countries probably have a national association so of course Australia does, America does and many more.
I recommend looking at

boomerangs.com
Boomerang Association of Australia
and
boomerangs.org

But in all honesty how good of a weapon is a boomerang? They are really light and there's very little information about them being used as a weapons (perhaps even some dispute) but it sounds like you can throw them super fast and the edges could be sharp-ish so maybe... According to this site much heavier throwing sticks would have done most of the killing while boomerangs would have been either for communiction or distraction. For a really brief history of boomerangs checkout the REDI or Boomerang Association of Australia websites.

I'd be willing to bet that a real-live Batman would use BatShuriken not Batarangs. In fact, many comics show Batman throwing sharp objects that don't return and this is definitely what the modern family of movies shows. Shuriken are considered non-lethal weapons that are used mainly for distraction purposes. They would be perfect for Batman...
But the Batarang is definitely more canonical or mainstream or classic and so we'll learn to use it first.