AirZooka Equations for Robotics Projects

[cnblock]

I may be making a little RC-car type robotics project, and I would like to make a sort of armament for it which is non-lethal, and kind of funny.

I have come to the realization that I can probably project sound using an air-zooka found on amazon, if I were to 3d print, or create out of household parts. I could put a speaker system in the back of the air-zooka and make it project sound a great distance, hopefully.

I however am not a physicist, therefore am completely unable to determine how to preform the equations for such a device. I am a software developer and can create a software program for determining desperate types based on off the shelf speakers provided I am told how to calculate their air displacement etc. This means that if someone were to provide me a formula which does not involve calculus I could have the software determine based on your formula exactly how to make the zooka based on different speaker types.

 

[anorlunda]

I'm not familiar with air zooka. Is it something like this?

 

[berkeman]

I think it's more like the following. I remember spring-loaded toys like this from when I was a kid in the mid-1960s (from Wham-O, I think):

https://www.thinkgeek.com/images/products/additional/carousel/60b6_airzooka_inhand.jpg

ADD -- Looks like the old Wham-O toy was the "Air Blaster": https://c1.staticflickr.com/5/4052/4307754375_3e6263bf89.jpg

 

[anorlunda]

OK got it. I'm older than the rest of you. My childhood toys were more like this.

Just kidding. Or am I?

 

[cnblock]

Right, I am fairly sure the only thing that matters is the diameter of the hole in relation to distance and volume of air moved. These things fire pretty far. I am reasonably certain like a rifling equation these would make small speaker emit pretty far distances, since it is in fact moving air. Thanks for the help if you indeed render it. Additionally, perhaps ada-fruit, jameco, or sparkfun some other electronics vendor would be interested in the equations. Thanks.

 

[berkeman]

I may be making a little RC-car type robotics project, and I would like to make a sort of armament for it which is non-lethal, and kind of funny.

I have come to the realization that I can probably project sound using an air-zooka found on amazon, if I were to 3d print, or create out of household parts. I could put a speaker system in the back of the air-zooka and make it project sound a great distance, hopefully.

Right, I am fairly sure the only thing that matters is the diameter of the hole in relation to distance and volume of air moved. These things fire pretty far. I am reasonably certain like a rifling equation these would make small speaker emit pretty far distances, since it is in fact moving air.

I'm not understanding what you are saying about a "speaker" and "project sound" in the context of an AirZooka or Air Blaster type toy weapon. The AirZooka and Air Blaster shoot out a pulse or knuckle of air, which travels for some distance before dissipating. That air knuckle can knock over stacked playing cards, or mess up a person's hair, and so forth. There is not really a sound associated with the air knuckle itself.

If you are just wanting to "project sound" (which is not really a weapon per se), you would use a different structure to do that. Are you familiar with how parabolic reflector structures are used to reflect and concentrate sound?

 

[cnblock]

I think first you are going to have to explain how concentrated air is not similar to a sound vibration which is also concentrations of air.

 

[berkeman]

I think first you are going to have to explain how concentrated air is not similar to a sound vibration which is also concentrations of air.

I think the pulse of air from an AirZooka is more like a soliton: https://en.wikipedia.org/wiki/Soliton

Versus a continuous longitudinal sound wave in air: https://en.wikipedia.org/wiki/Sound

 

[Stephen Tashi]

If the piston or diaphram that created the pulse of air could exceed the speed of sound (in air) then can we create a "sonic boom"?
I've read that sounds like the cracking of a whip are produced by everyday objects exceeding the speed of sound for short times.
I wonder if loud noises like hitting a board with a hammer are examples of that.

 

[Tom.G]

I think first you are going to have to explain how concentrated air is not similar to a sound vibration which is also concentrations of air.

Consider that the lower frequency limit of human hearing is 20Hz. With sound traveling about 1100ft. per second (330m per sec.), a 20Hz sound will have a rise time around 18ms, anything slower than that the human ear does not perceive as sound.

Your AirZooka is like tossing a basketball of air, it is traveling perhaps a few feet per second; not a fast enough rise time for your ear to discern as sound.

The most you could expect is a feeling similar to the pressure change when driving up and down a mountain or in an airplane at takeoff and landing; and even that would be minimal if detectable at all.

Cheers,
Tom

 

[Stephen Tashi]

Your AirZooka is like tossing a basketball of air, it is traveling perhaps a few feet per second;

I think of sound as result of air molecules transmitting small vibrations and wind as a gross transport of air molecules. Is an AirZooka pulse an intermedate effect? Something like a turbulence that is locally a gross movement of air molecules?

 

[Bystander]

Think "smoke-ring" without the smoke. Also, the five inch thirty-eights from WW II would sometimes blow smoke rings; http://cdm16099.contentdm.oclc.org/cdm/singleitem/collection/p16099coll1/id/499/rec/248 .