Tuesday, December 2, 2008

Shiny New Parts

This is the injector for the next version of the N2O-Propane engine.


Ben Brockert said...

Ooh, shiny.

Are the outer six holes for film cooling? Does film cooling work with that few injection elements?

Rocket Dude said...

I suppose the answer is "sort of". I would have liked to have more holes around the perimeter for film cooling, but minimum machinable hole diameters would have made the percentage of total flow more than I wanted.

CFD shows that the outer holes will have some limited film cooling effet. Their other main purpose is to bias the mixture ratio even more rich at the wall (I plan to run the motor rich overall).

The chamber will be regeneratively cooled as well. Hopefully between the film cooling, the mixture bias, the regenerative cooling, and soot buildup, I can keep things from melting.

Ben Brockert said...

Interesting. Does the igniter go in the middle, or is there more injector stuff there?

Rocket Dude said...

The middle is threaded for either a spark plug or igniter. (10x1 mm)