Ignition System | Hybrid engine discussion | Forum

Post edited 10:44 pm – December 12, 2010 by Nick

Hey guys, Sorry i've been absent. been a busy month.

I've seen some ideas tossed around for an ignition system, and I thought I would share my experiences.

The system I am going to show you is based off of a commercial solution, not sure which, but adapted to the specific engine we tested.

The basic theory is to flood the Chamber with GOX and ignite it. Combustion starts, and when the engine is hot enough, N2O is released from the tank and the engine ignites fully.

Here is a  Drawing i did in MS paint (Sorry i don't have any Modeling software installed on this PC)

The Filler Assembly Is attached to the back of the motor using a zip-tie or something similar. When it melts through, It is released and shot away from the back of the motor.

Here is a picture of one being installed. You can see the zip-ties beign installed, and the 2 Fuel lines.

And then a picture of the Assembly after ignition.

Closeup of it installed

Moments before ignition.

and finally, ignition!

Check out http://www.hypertekhybrids.com…..manual.pdf This is what we based our system on. Yes, the oxidizer is filled through the tail end of the rocket, which in my opinion makes the construction simpler. (no need to have ports on the side of the body to fill, would require no access to the tank to fill, You fill moments before ignition- no need to have a live rocket when setting it up on the pad.  ect…)

This system uses a simple injector port, that the fillertube seals into. Using an injector plate would complicate this, but it may be able to be adapted. I don't have the numbers right now, but i remember from our research that the GOx would ignite easier using speaker wire hooked up to a transformer which took a car battery and pumped 2300 volts through 24 gauge speaker wire "cut into a V" which arced and burned the insulation of the wire. The wires are taped up the filler tube of the rocket and are left behind at launch. We had 100% success with ignition on all of our test fires.This was used with HTPB, I haven't been able to find any Technical HDPE hybrid rocket data, mostly just homemade systems.