On 4/22/2018 12:19 PM, Henry Spencer wrote:
Thinking of this, it occurs to me that if you *must* experiment with mixed monoprops, the way to do preliminary tests would be to store the fuel and oxidizer separately on the test stand, and mix them in the plumbing just before they reach the chamber. (Such "premixing injectors" saw some use in the early days of rocketry, although injector explosions were common enough that the technique went out of fashion.)
This doesn't *eliminate* the possibility of explosions, but at least it limits the amount that can go up at once. It may not do that entirely effectively if one of the components is itself a monoprop, like nitrous, but it should reduce the hazards some.
If your favorite mix gives reliable, repeatable engine startup and operation without injector explosions -- probably it won't -- *then* you can think about adding a tank in the middle, where you do the mixing (still by remote control, please) before engine start.
Still later would come more-flight-weight systems where the mixing happens at fill time.