Abstract: The water rocket engine with a two-phase nozzle includes a water rocket propulsion system having a reservoir, and a nozzle assembly disposed along a central longitudinal axis therein, the nozzle assembly comprising an inverted cup shaped fluid capture vessel having a substantially concave sidewall and extending away from an elongated tube. Open lower portion of the fluid capture vessel forms a fluid inlet. The elongated tube has a concave shaped side wall that forms a nozzle gas inlet at an upper portion of the tube, a nozzle outlet at a lower portion of the tube, and a passageway disposed between the tube upper portion and the tube lower portion. Within the confines of the capture vessel, fluid injection holes are disposed in the tube sidewall to provide fluid intake into the nozzle passageway where fluid and gas combine to form a two phase propellant.

Abstract: The water rocket engine with a two-phase nozzle includes a water rocket propulsion system having a reservoir, and a nozzle assembly disposed along a central longitudinal axis therein, the nozzle assembly comprising an inverted cup shaped fluid capture vessel having a substantially concave sidewall and extending away from an elongated tube. Open lower portion of the fluid capture vessel forms a fluid inlet. The elongated tube has a concave shaped side wall that forms a nozzle gas inlet at an upper portion of the tube, a nozzle outlet at a lower portion of the tube, and a passageway disposed between the tube upper portion and the tube lower portion. Within the confines of the capture vessel, fluid injection holes are disposed in the tube sidewall to provide fluid intake into the nozzle passageway where fluid and gas combine to form a two phase propellant.