The present invention discloses a multistage variable burning rate solid rocket motor and a forming method. A multi-material composite fiber skeleton structure is embedded inside a propellant in the present invention, so that the original burning rate of the propellant presents multistage changes to achieve the function of multistage thrust. The fiber skeleton structure embedded in the solid rocket motor is formed by additive manufacturing, fixed in a combustion chamber, and then charged at one time to complete the forming of a motor grain. The design can greatly increase the burning rates of the propellants of end-burning and bore-burning motors, and can also conduct multistage adjustment for the burning rates of the motors by changing the fiber skeleton and structure, so as to satisfy the requirements of missile weapon systems for multistage power propulsion. The present invention greatly simplifies the technological production process of the existing single-chamber multi-thrust motor.

The present invention discloses a multistage variable burning rate solid rocket motor and a forming method. A multi-material composite fiber skeleton structure is embedded inside a propellant in the present invention, so that the original burning rate of the propellant presents multistage changes to achieve the function of multistage thrust. The fiber skeleton structure embedded in the solid rocket motor is formed by additive manufacturing, fixed in a combustion chamber, and then charged at one time to complete the forming of a motor grain. The design can greatly increase the burning rates of the propellants of end-burning and bore-burning motors, and can also conduct multistage adjustment for the burning rates of the motors by changing the fiber skeleton and structure, so as to satisfy the requirements of missile weapon systems for multistage power propulsion. The present invention greatly simplifies the technological production process of the existing single-chamber multi-thrust motor.

In a rocket motor in which burn rate enhancement (BRE) wires are used to accelerate the burn rate of the solid propellent, embedded charge assemblies (ECAs) are configured as support structures for the BRE wires. Each ECA includes an energetic material that is configured to burn along with the solid propellent to produce thrust and, upon detonation, to break up the solid propellent to terminate thrust. The detonation may also be initiated as a part of process to prevent a higher-order reaction, such as in reaction to heating from a fire or other cause. By being located inside the casing, the energetic material and ECAs do not adversely affect aerodynamics of the flight vehicle of which the rocket motor is a part, such as a missile.

In a rocket motor in which burn rate enhancement (BRE) wires are used to accelerate the burn rate of the solid propellent, embedded charge assemblies (ECAs) are configured as support structures for the BRE wires. Each ECA includes an energetic material that is configured to burn along with the solid propellent to produce thrust and, upon detonation, to break up the solid propellent to terminate thrust. The detonation may also be initiated as a part of process to prevent a higher-order reaction, such as in reaction to heating from a fire or other cause. By being located inside the casing, the energetic material and ECAs do not adversely affect aerodynamics of the flight vehicle of which the rocket motor is a part, such as a missile.

The present invention is a system and method for manufacturing a modular motor architecture, comprising a rocket motor comprising an extended case with a forward end and an aft end. The forward end features a radial retention interface with a multi-stack polar boss, a multi-stack forward polar boss enclosure, and radial tabs. The multi-stack polar boss is molded using boss molding material into three to twenty radial tabs and is wound into the composite case. The motor includes multiple multi-stack cartridges that house propellant and a central combustion chamber. These cartridges, including a forward cartridge, a primary cartridge, and an aft cartridge, are suspended inside the case and secured co-axially with the composite case by various joints, including polar and aft joints. The aft cartridge is located at the aft end, which features a closure and a nozzle.

The present invention is a system and method for manufacturing a modular motor architecture, comprising a rocket motor comprising an extended case with a forward end and an aft end. The forward end features a radial retention interface with a multi-stack polar boss, a multi-stack forward polar boss enclosure, and radial tabs. The multi-stack polar boss is molded using boss molding material into three to twenty radial tabs and is wound into the composite case. The motor includes multiple multi-stack cartridges that house propellant and a central combustion chamber. These cartridges, including a forward cartridge, a primary cartridge, and an aft cartridge, are suspended inside the case and secured co-axially with the composite case by various joints, including polar and aft joints. The aft cartridge is located at the aft end, which features a closure and a nozzle.

A rocket motor comprises at least two propellant grains/grain segments; a case comprising the propellant grains/grain segments, stacked within the case; and a resin for substantially maintaining the grains/grain segments in position within the case. In another aspect, a rocket motor comprises at least two propellant grains/grain segments, each having an aft-end face and a fore-end face. At least two of the propellant grains/grain segments comprise a sleeve having propellant cast therein. The motor further comprises a case comprising the propellant grains/grain segments, stacked within the case, wherein the sleeve of one propellant grain/grain segment is coupled to the sleeve of an adjacent propellant grain/grain segment such that the fore-end face of one grain/grain segment is spaced from the aft-end face of an other grain/grain segment creating a gap therebetween. Methods for making the rocket motors are described.

A rocket motor comprises at least two propellant grains/grain segments; a case comprising the propellant grains/grain segments, stacked within the case; and a resin for substantially maintaining the grains/grain segments in position within the case. In another aspect, a rocket motor comprises at least two propellant grains/grain segments, each having an aft-end face and a fore-end face. At least two of the propellant grains/grain segments comprise a sleeve having propellant cast therein. The motor further comprises a case comprising the propellant grains/grain segments, stacked within the case, wherein the sleeve of one propellant grain/grain segment is coupled to the sleeve of an adjacent propellant grain/grain segment such that the fore-end face of one grain/grain segment is spaced from the aft-end face of an other grain/grain segment creating a gap therebetween. Methods for making the rocket motors are described.