IceX: Steam Assisted Rocket Project continued

Dienstag, Juli 12, 2011

Steam Assisted Rocket Project continued

Steam Assisted Rocket Project continued: "

Rick reports:

The new design I was trying is partly based on the Sugar Shot dual pulse motor design. The motor is filled half full of propellant with a cylindrical core to the top. I then packed paper into the tube on top as a 'delay' grain. I then poured more propellant on top of that again with a cylindrical core. I idea is that the lower propellant is ignited propelling the rocket upwards and then coasts as the paper burns through. Then the second pulse (the propellant first poured) fires.

How this 'should' increase the steam assisted portion of the flight is this: the first pulse launches the rocket and clears an 'open blast tube' in the lower portion of the motor. A small portion of the heat from this process goes into the motor casing (water jacket) since the unburned propellant had been acting as an insulator and the heat didn't get to the motor casing in any large amount until it was burning near the casing and some conduction from the nozzle. When the second pulse fires, the heat from this combustion is always in contact with the motor casing, with the water acting as a heat sink protecting the motor casing and becoming superheated. When the propellant completely burns away it releases the steam through the motor casing picking up more heat, blasting out the residual byproducts of the sugar combustion. Yesterday was a test of just the sugar dual thrust idea without the water jacket.

After successfully testing this idea, while making a drawing of this sequence, I came to the realization that a pure regressive motor would transfer the greatest amount of heat to the motor casing and into the cooling water converting it into super heated water to flash into steam at the conclusion of the propellant burn. See drawing and video.

Since the entire motor casing would be exposed to the propellant burning for the total burning time, the regressive should offer the greatest heat absorption from the combustion. In addition, the greatest thrust would be at the beginning of the burn to lift the rocket off the test stand. A water-cooling jacket protecting the motor casing could absorb enough heat to then flash to steam to assist the motor in propelling the rocket higher. (Water-cooling jacket surrounding motor casing not shown.)

(Drawings and video courtesy Rick Maschek)