Patent ID: 8381528

Claim:
A regenerative superheater system for a ramjet engine, comprising: (a) a fixed-geometry superheater in thermal communication with a combustion chamber of the ramjet engine; (b) a fluid reservoir in fluid communication with the superheater, wherein fluid flows from the reservoir through internal passages in the superheater, wherein thermal energy is exchanged from the combustion chamber to the fluid; (c) a cooler in fluid communication with the superheater, wherein the cooler includes a hot side and a cold side in thermal communication with each other, wherein superheated fluid from the superheater enters the hot side of the cooler and loses thermal energy to the cold side of the cooler according to a temperature differential between the cold side and the hot side; (d) a subsonic diffuser with a variable-geometry air inlet and a subsonic nozzle with a variable-geometry exit in fluid communication with the cold side of the cooler, wherein the temperature differential between the hot side and the cold side of the cooler is modulated by time-varying geometry of the subsonic diffuser and subsonic nozzle; and (e) a delivery line that redirects the fluid upstream of the combustion chamber from the hot side of the cooler to a fluid ejector that ejects the fluid into an inlet of the ramjet engine.