On 1/28/2014 12:08 PM, Henry Baker wrote:
Actually, the miniature .049 glow-plug model airplane engines _are_ diesels, as they don't have any ignition.
I seem to recall that in the good ol' days before cars had electric starters, you had to crank the engine to start it. If you weren't aggressive enough, the car would kick back & possibly run backwards for a bit, breaking your arm in the process. Ditto for farm tractors.
The problem with jet engines is that they aren't symmetrical: the blades have an orientation. Furthermore, trying to stuff air backwards through the exhaust into the intake won't work, either, because the fuel injectors aren't in the right place.
So-called scramjets don't appear to have any moving parts at all, much less rotating parts, so there is no chirality.
Chirality? There's directionality. The compression ramp isn't the same as the expansion ramp and the fuel (H2) has to be injected on the compression side in order to get it to burn soon enough to provide thrust. Brent