Patent ID: 9726115
Date: 2017-08-08
CPC Classifications: F02K

Claim:
1. A selectable ramjet propulsion system for propelling a missile, comprising: a variable flow ducted rocket having a gas generator, a combustor, a frangible diaphragm, and an inlet duct, wherein the a gas generator has a center-perforated grain solid rocket propellant, wherein the center-perforated grain solid rocket propellant of the gas generator is a ramjet fuel, wherein the gas generator is adjacent the combustor, wherein the combustor has a center-perforated grain solid rocket propellant, wherein the frangible diaphragm is disposed between said gas generator and said combustor, wherein the frangible diaphragm is configured to withstand an approximate 2000 psia boost pressure from the combustor, yet to yield upon a pressure lower than the boost pressure from the gas generator prior to an ignition of the center-perforated grain solid rocket propellant of the combustor, wherein the inlet duct is selectively fluidly coupled to the combustor via a port cover, and wherein the surface area of the frangible diaphragm is sized to allow an unchoked subsonic flow of a gaseous product of a combustion of the gas generator center-perforated grain solid rocket propellant into the combustor.