Abstract: A propulsion unit for the acceleration of a self-propelled vehicle, such as a missile or a rocket, is loaded with a propellant block secured laterally to the body of the propulsion unit by means of a combustion inhibitor and has an aspect ratio of between 2.5 and 6. The propellant block has one axial duct and at least 6 peripheral ducts and, on its upstream face, is equipped with a fitting secured to the body of the propulsion unit. This fitting provides a free space between the upstream face of the propellant block and the bottom of the body of the propulsion unit, the axial duct and the peripheral ducts opening into this free space via orifices made in the fitting. The combustion gases are ejected rearward without being fed through a nozzle. Sonic velocity is achieved downstream of the ducts.

Abstract: The invention concerns a propulsion device for acceleration of a self-propelled engine, such as a missile or a rocket. The propulsion device comprises a body (1) equipped with a nozzle (2) and a block of propellant (3) having a longitudinal central duct (4) of variable section. The block of propellant comprises a downstream part (5) having a cylindrical duct (6) which has a circular section whose diameter is less than two thirds of the diameter of the throat of the nozzle (2) and an upstream part (7). The duct (8) of this upstream part (7) on the one hand has a diameter which exceeds the diameter of the duct (6) of the downstream part and is less than the diameter of the throat of the nozzle (2), and on the other hand is connected to the duct (6) of the downstream part by a portion in the shape of a truncated cone (9).