A solid-propellant gas generator assembly may comprise a bulkhead having an orifice disposed in a housing. The bulkhead may be disposed between a first end and a second end of the housing. The bulkhead and the first end may define a propellant cavity. The bulkhead and the second end may define a pressure chamber. A fast burning solid-propellant may be disposed in the propellant cavity. The solid-propellant gas generator assembly may be configured to replace a slow burning solid-propellant gas generator system in a solid-propellent gas generator system.

The present invention is a composite solid propellant designed to operate in three distinct combustion regimes under various pressure states in the combustion chamber of a solid rocket motor. The design of this propellant facilitates desirable rocket motor operational characteristics, including throttleability, extinguishment, and self-destruction or detonability. The propellant contains ingredients that modify the propellant combustion characteristics to provide the desired behavior, including a surfactant and unaggregated, unagglomerated dispersed primary nanoparticles of aluminum in a polymer binder.

The present invention is a composite solid propellant designed to operate in three distinct combustion regimes under various pressure states in the combustion chamber of a solid rocket motor. The design of this propellant facilitates desirable rocket motor operational characteristics, including throttleability, extinguishment, and self-destruction or detonability. The propellant contains ingredients that modify the propellant combustion characteristics to provide the desired behavior, including a surfactant and unaggregated, unagglomerated dispersed primary nanoparticles of aluminum in a polymer binder.

A readily combustible portion (110) includes a readily combustible exposed surface (111) that is exposed to a flow channel (CA). A combustion-resistant portion (140), which comprises a material that is more resistant to combustion than the readily combustible portion (110), covers an outer surface of the readily combustible portion (110) on the opposite side from the readily combustible exposed surface (111) in a direction orthogonal to a length direction parallel to a direction in which a hybrid rocket is propelled. The combustion-resistant portion (140) includes a thick portion (120) that serves as a stopper that prevents peeling of the readily combustible portion (110) from the combustion-resistant portion (140) in a direction from a starting end surface (100a) toward a terminating end surface (100b).

A readily combustible portion (110) includes a readily combustible exposed surface (111) that is exposed to a flow channel (CA). A combustion-resistant portion (140), which comprises a material that is more resistant to combustion than the readily combustible portion (110), covers an outer surface of the readily combustible portion (110) on the opposite side from the readily combustible exposed surface (111) in a direction orthogonal to a length direction parallel to a direction in which a hybrid rocket is propelled. The combustion-resistant portion (140) includes a thick portion (120) that serves as a stopper that prevents peeling of the readily combustible portion (110) from the combustion-resistant portion (140) in a direction from a starting end surface (100a) toward a terminating end surface (100b).

A fuel grain for a hybrid rocket engine includes multiple, concentric cylindrical layers of fuel grain material defining a combustion port extending axially through the fuel grain, in which each layer includes multiple beads of fuel grain material, in which the multiple beads in a given layer are disposed adjacent to one another and bonded together, and in which adjacent concentric layers are bonded together. Each bead of fuel grain material includes a polymer based rocket fuel material and a nanoscale metallic material, and a composition of the beads of the fuel grain material varies along a radius of the cylindrical fuel grain.

A fuel grain for a hybrid rocket engine includes multiple, concentric cylindrical layers of fuel grain material defining a combustion port extending axially through the fuel grain, in which each layer includes multiple beads of fuel grain material, in which the multiple beads in a given layer are disposed adjacent to one another and bonded together, and in which adjacent concentric layers are bonded together. Each bead of fuel grain material includes a polymer based rocket fuel material and a nanoscale metallic material, and a composition of the beads of the fuel grain material varies along a radius of the cylindrical fuel grain.

Solid propellant systems include a main propellant and a secondary propellant in contact with the first propellant that exhibits autoignition temperatures of at least about 100° F. lower than the autoignition temperature of the main propellant. The secondary propellant of the present invention is most advantageously employed with conventional AP-containing solid propellant formulations as the main propellant, especially formulations containing both AP, an energetic solid, and a binder. In especially preferred forms, the secondary propellant will include a nitramine which is at least one selected from nitroguanidine (NQ), cyclotrimethylene trinitramine (RDX) and cyclotetramethylenetetranitramine (HMX), and a binder which is at least one selected from HTPB, HTPE or glycidyl azide polymer (GAP). Most preferably, the secondary propellant will include a combination of nitramines which includes NQ and one of RDX or HMX.

Solid propellant systems include a main propellant and a secondary propellant in contact with the first propellant that exhibits autoignition temperatures of at least about 100° F. lower than the autoignition temperature of the main propellant. The secondary propellant of the present invention is most advantageously employed with conventional AP-containing solid propellant formulations as the main propellant, especially formulations containing both AP, an energetic solid, and a binder. In especially preferred forms, the secondary propellant will include a nitramine which is at least one selected from nitroguanidine (NQ), cyclotrimethylene trinitramine (RDX) and cyclotetramethylenetetranitramine (HMX), and a binder which is at least one selected from HTPB, HTPE or glycidyl azide polymer (GAP). Most preferably, the secondary propellant will include a combination of nitramines which includes NQ and one of RDX or HMX.

Solid propellant systems include a main propellant and a secondary propellant in contact with the first propellant that exhibits autoignition temperatures of at least about 100° F. lower than the autoignition temperature of the main propellant. The secondary propellant of the present invention is most advantageously employed with conventional AP-containing solid propellant formulations as the main propellant, especially formulations containing both AP, an energetic solid, and a binder. In especially preferred forms, the secondary propellant will include a nitramine which is at least one selected from nitroguanidine (NQ), cyclotrimethylene trinitramine (RDX) and cyclotetramethylenetetranitramine (HMX), and a binder which is at least one selected from HTPB, HTPE or glycidyl azide polymer (GAP). Most preferably, the secondary propellant will include a combination of nitramines which includes NQ and one of RDX or HMX.