New Hybrid Design?

by **An Apple Pie** » Sat Dec 30, 2006 9:41 pm

Okay I just thought of a new type of design for a hybrid type launcher. I have no idea how well this would work or wouldn't work, so I am here to ask you guys.

The main difference between this and a normal hybrid would be that the gases are accelerated before they are ignited.

This design would consist of one chamber (where the fuel and air are mixed and pressurized) and then another chamber with just air and a spark. The chambers would be separated by a burst disk.

The picture pretty much explains how it works so here you go.
<img src="http://www.spudfiles.com/uploader/uploadFiles/Hybridtypedesign2.JPG">

Sorry if this is going to be some sort of bomb:x. I am not planning on constructing this any time soon. Just throwing the idea out there.

-EDIT-
Diagram updated

by **TurboSuper** » Sat Dec 30, 2006 10:47 pm

How do you plan on breaking the burst disk and maintaining the right stochiometric ratio of propane to air?

The secondary chamber would probably also mess with that ratio.

Ultimately, I really don't see what this does that a regular Hybrid doesn't do, the non reactive components of the air are still producing pressure regardless of whether the mix is ignited or not.

by **Zorrowannabe9** » Sat Dec 30, 2006 10:52 pm

This would be less efficient in my opinion. As the mixture moves into the second chamber it would push the projectile down and most likely out of the barrel. This would in my opinion be a pneumatic with a late muzzel flash. Also the work to get the timing of the spark and controling the breaking of the burst disk would be far to much work for no gain over a typical hybrid design or even a pneumatic for that matter.

by **An Apple Pie** » Sat Dec 30, 2006 11:34 pm

I am not sure what you would use for the amount of propane. I am leaving that for somebody else to figure out.

The actual combustion chamber is much smaller than actually shown. It would probably be just be the length of the reducing fitting. And as for the spark I was thinking of something with a continuous spark. I forgot what kind of device creates this, but I know I have heard about them.

You could use a fairly long barrel to compensate for the inefficiency.

Oh, and for triggering the burst disk, I was just thinking about having the compressed air burst it. I now realize that because the burst disks may not always burst at the exact same PSI, that the propane/air ratio will be messed up. Maybe a triggered burst disk, or maybe just a piston valve, or something of the sort.

-EDIT-
Forgot to answer question on burst disk.

**Sponsored**

by **Zorrowannabe9** » Sat Dec 30, 2006 11:37 pm

This requires the same materials as a standard hybrid...its just more complex with no real gain in performance from what i can see. If you plan on making a hybrid, I would not use this plan.

Too answer your question...a tazer can create a longer (time) spark gap

by **An Apple Pie** » Sat Dec 30, 2006 11:42 pm

How is this more complex?

I also think there would be quite a significant gain in power. It is basically the power of a hybrid ontop of the power of a pneumatic.

The combustion in a hybrid obviously accelerates the air. Now with this design the combustion is accelerating already accelerated fuel. This creates higher FPS, and therefore higher power.

by **spuzi14** » Sun Dec 31, 2006 12:33 am

Well actually isn't somebodies law at work here? I want to say Boyle.

Something like putting a certain amount of pressure over a small space makes more pressure? I don't know if that's a law or whatever but anyway....

If the 1st chamber was pressurised to say 50 PSI and propane was added, you would have to add the amount of propane for the combined volume of the first and second chamber. Propane first, then compressed air. The compressed air has reached 50 PSI and the disk bursts and your air and propane go into a smaller chamber. Wouldn't that create more pressure especially after igniting the propane?

I don't know really if that was even relative to the picture above. I looked at it and assumed (possibly making an "ass" o"u"t of "me"). The only drawback if my idea is correct in concept is that the air and fuel would move backwards into chamber 1 instead of forward. Maybe a check valve?

by **An Apple Pie** » Sun Dec 31, 2006 12:43 am

Setting aside power, the one main advantage to this design is that you could use a ball valve or something. You wouldn't have to keep replacing the burst disk. You could also use a piston valve if it didn't have o-rings. Something tells me all the heat would destroy the seals. Actually the heat might destroy the neoprene too. I could be wrong, but using a ball valve sounds much more appealing to me than having to repalce a burst disk after every shot.

by **Zorrowannabe9** » Sun Dec 31, 2006 1:26 am

spuzi-the chamber isnt getting smaller, its actually getting larger. When the valve of some form is opened the second chamber and first chamber become one, they become a larger chamber.

apple- I could see an advantage if you were to use a ballvalve or piston, or even a diaphragm (if it didnt melt.) The gained speed in not requiring replacment of burst disks would be easier to use. You did not make this distinction in your original drawing, but it seems viable. A ball valve would be far too slow though.

by **clide** » Sun Dec 31, 2006 2:10 am

Somebody did this on the old forums. I believe they used a sprinkler valve or two for the valve. So if you consider this a hybrid then it was actually the first kind.