Aluminum combustion chamber

[jyoung]

I see that on the bailey dynajet plans call for aluminum on the valve head, but steel for the combustion chamber and resonator tube. Is there a reason why I could not use aluminum instead? temp? Pressure?

[Rossco]

Ha, NO you cant!
Heat, heat, and more heat!

Too much work in it to melt in a fraction of a second. Sheet steel would be much easier to build anyway. Even mild handles it fine... for a while, if its adequetly thick. Youll get many, many a run before the flakes of oxidization start getting thicker than the steel. (this does happen)

Have a look through some of the video here, to get an idea of the heat generated. Even the radiant heat has to be taken into consideration when mounting.

Rossco

[Mike Everman]

Yeah. While it might be a split second of fun, watching it consume itself, that's a lot of work for performance art. At least it won't grenade and splatter you with molten aluminum, it will most likely fail in the low pressure end, suck a hole, sag, *cry*

[jyoung]

allright well I guess I will have to go ahead and roll a combustion chamber cone out of steel. Has anybody ever calculated what type of force is being exerted on the walls of the chamber?

[Stuart]

allright well I guess I will have to go ahead and roll a combustion chamber cone out of steel. Has anybody ever calculated what type of force is being exerted on the walls of the chamber?

Most pulsejets are showing a peak to trough fluction of 2 atmospheres (30 psi. Most failures that have been documented on this site are vacuum collapse. That should get you some ballpark idea.

Need more pressure Scotty if we're going to make warp 9! !