Ever wonder how a hybrid rocket motor gets lit up?

You may recall from my previous post about hybrid motors, that they consist of 2 separate parts - a hollow tube-like component filled with solid (in itself inert) fuel, and a tank of oxidizer fluid with some plumbing that forces the fluid to get flushed through the aforementioned hollow part of the tube-like solid fuel.

That's cool and all, but without the presence of a spark that can light this whole thing up, and start the chemical reaction, all you are left with is what we in the biz call a 'cold flow'.

A 'cold flow' means just that, no spark, no fire, no reaction, just some cold fluid flowing through some solid rocket fuel. To the observer, this is typically rather uneventful. Though it is kinda cool to watch.

*This entry contains a YouTube video*

Cold Flow test. The mass flow rate change was the testing of different positions of valve opening settings.

Now, cold flow tests are great to have. They prepare you for the real deal. You get to test all your instrumentation, validate your sensors, make sure your timing sequences are . . . More