Liquid monopropellant gun

• US 4,953,440 A
• Filed: 11/26/1975
• Issued: 09/04/1990
• Est. Priority Date: 11/26/1975
• Status: Expired due to Term

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Moscrip, William M.
• Primary Examiner(s): Brown, David H.
• Application Number:
  US05/636,342
• Time in Patent Office: 5,396 Days
• Field of Search: 89/8, 89/7, 73/167, 60/39.46 M
• US Class Current: 89/7
• CPC Class Codes: F41A 1/04 Missile propulsion using the combustion of a liquid, loose powder or gaseous fuel, e.g. hypergolic fuel

Abstract

A gun in which the interior wall of the breech portion of the bore is proed with a series of small annular combustion chambers distributed along the axis which are filled with liquid monopropellant to provide a propellant lined breech. Propellant is pumped into the annular combustion chambers through ports or fill orifices which communicate with an annular chamber surrounding the breech. This construction of the propellant in a series of small discrete volumes which eliminates the hydrodynamic instabilities associated with combustion of bulk loaded liquid propellants.

Claims

1. A liquid monopropellant gun having a propellant lined breech when ready for firing comprising:

a gun tube;

a breech fixed to one end of said gun tube;

a plurality of annular combustion chambers formed on the interior wall of said breech, the interior wall of each of said combustion chambers being defined by the surface of a projectile introduced into said breech; and

means for introducing liquid monopropellant into said annular combustion chambers.

2. A gun as defined in claim 1 wherein said propellant introducing means includes:

a jacket surrounding said breech and spaced therefrom to define a loading chamber therebetween; and

at least one fill orifice formed in said breech to provide fluid communication between each annular combustion chamber and said loading chamber, said fill orifices being of sufficiently small diameter to preclude propagation of a flame front from said combustion chambers into said loading chamber.

3. A gun as defined in claim 2 wherein said propellant introducing means further includes:

a propellant reservoir; and

means for pumping liquid monopropellant from said reservoir into said loading chamber and through said fill orifices into said annular combustion chambers.

4. A gun as defined in claim 1 wherein said annular combustion chambers are defined by a plurality of inwardly projecting flanges formed integrally with said breech and having an inner diameter equal to the nominal diameter of the projectile whereby sequential ignition of discrete volumes of propellant is obtained as the projectile moves along the breech toward the gun tube, the rate of ignition being governed by projectile velocity.

5. A gun as defined in claim 4 wherein said propellant introducing means includes:

a jacket surrounding said breech and spaced therefrom to define a loading chamber therebetween; and

at least one fill orifice formed in said breech to provide fluid communication between each annular combustion chamber and said loading chamber, said fill orifices being of sufficiently small diameter to preclude propagation of a flame front from said combustion chambers into said loading chamber.

6. A gun as defined in claim 5 wherein said propellant introducing means further includes:

a propellant reservoir; and

means for pumping liquid monopropellant from said reservoir into said loading chamber and through said fill orifices into sid annular combustion chambers.