Andrew Case wrote: > If the length of the plumbing between valve and injector is different > for fuel & ox, then simultaneous shutdown of the main valves ought > to lead to a timing difference in the shutdown _at_the_injectors_. > This obviously glosses over issues like differences in plumbing diameter, > propellant viscosity, fuel/ox mixture ratio, etc, but it illustrates the > point. For a regen HTP biprop, the additional volume in the engine cooling > passages ought to make it relatively simple to ensure that a scram shutdown > with purge leads to fuel exhaustion well before HTP exhaustion. > > IOW if there is substantially more volume in the HTP plumbing between > main valve and injector then between fuel valve and injector, then > the purge you describe ensures that in most scram scenarios the > catpack is protected.
Perzackly. In our LOX/alcohol engines, the fuel is the coolant and due to the longer flow path, is the last to be purged out. This gives us an increasingly rich shutdown transient and excellent coolant during the transient, which prevents a themal spike. It also makes for a showy flash of external flame :) Doug _______________________________________________ ERPS-list mailing list [EMAIL PROTECTED] http://lists.erps.org/mailman/listinfo/erps-list
