tmacklin
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Does a D12-0 really have any "bang powder?" Is there an ejection charge at all? My understanding has always been that it does not have an exploding ejection charge --- all it has is a single fuel grain that provides thrust and burns through at the end, allowing hot gas forward. There isn't an explosion, just a burn through with a couple seconds of flame and pressure. It seems like if the zero motor were secured tightly against a flame-proof bulkhead, that would be adequate. You would NOT want to retain a motor with an ejection charge against a bulkhead! BAM! But I think a zero-delay booster motor would work fine that way. The pressure would continue to vent out the nozzle, just like before the burn through.
As an end burning black powder motor with an ejection charge burns and provides thrust for propulsion, the grain diminishes in length until it comes in contact with and ignites a different composition known as a delay grain and the burn then continues at a much slower rate until it ultimately contacts the ejection charge which then deflagrates and bursts the clay cap, pressurizing the airframe and ejecting the recovery system.
As an end burning black powder booster motor burns and provides thrust for propulsion, the grain diminishes in length until it becomes so thin that a structural failure of the propellant grain occurs, breaking the remaining grain into smaller burning particles which take the path of least resistance which is suddenly forward and away from the nozzle. If this forward pressure is sufficiently retained, the booster casing will most likely be ejected backward out of the motor mount. However, if the cavity at the head of a booster motor is plugged with any material that is both non-flammable and sufficiently bonded to both the casing and the propellant grain, the motor will simply burn out and all of the propellant's gaseous products will be forced out of the nozzle.
My videos at post number 5 clearly illustrate what I just described.