Abstract: A solid fuel propulsion system includes a housing, an air inlet configured to enable air to flow into the housing, an air duct, a rotation detonation chamber, and a nozzle assembly. The air duct is disposed in the housing and is in fluid communication with the air inlet. The air duct is configured to supply air for combustion of a solid fuel configured to sublimate into a gaseous fuel mixture. The rotation detonation chamber is disposed in the housing aft of the air duct and is configured to combust the gaseous fuel mixture and air to generate a rotating detonation wave. The nozzle assembly is configured to expand and exhaust the flow prompted by the rotating detonation wave to generate thrust.

Abstract: A fluid properties sensing system includes an optical sensor which generates a sensor signal based on received laser light, a light source which transmits laser light through a transmitting fiber to a sensor head, a receiver that detects a portion of the laser light from a receiving fiber through an evanescent field of the transmitting fiber when the laser light radiates through a transmitting fiber wall of the transmitting fiber and interacts with a fluid medium at an interface of the sensor and the fluid medium, and a processor. The fibers are coupled at one end through the evanescent field to form the sensor head disposed in a flow field and to interact with the fluid medium. The processor identifies a change in the sensor signal based on a detected portion of the laser light resulting from an interaction of the sensor head with the fluid medium.

Abstract: This disclosure relates to systems and methods element identification and quantification. The method includes generating pulsed plasma based on an input voltage and a current so that the pulsed plasma interacts with a particle and atomizes the particle when the pulsed plasma is disposed in a flow field, identifying an atomic emission of the pulsed plasma with an optical sensor, determining element identification and quantification based on the identified emission of pulsed plasma, generating DC plasma having an electrical field based on an input DC voltage and a DC current, positioning the DC plasma in a flow field, detecting a change in the electrical field of the DC plasma, and determining a size of the particle based on the change in electrical field.

Abstract: This disclosure relates to a system for actively controlling shock train in a high speed, air-breathing propulsion engine. The system includes an isolator, a sensor associated with the isolator, and a shock train fuel injector in electrical communication with the sensor. The sensor is configured to sense changes in pressure generated by a shock train in the isolator. The shock train fuel injector is in electrical communication with the sensor. The shock train fuel injector is configured to modulate fuel flow to the engine to control back pressure produced by the engine in response to predetermined pressure changes in the shock train.

Abstract: This disclosure relates to systems and methods detecting a change in pressure, wall shear flow, or both. The method includes generating DC plasma having an electrical field based on an input DC voltage and a DC current, detecting changes to the electrical field, and identifying a change in wall shear flow, pressure, or both based on the change in the electrical field when the DC plasma is disposed in a flow field.

Abstract: A fuel reformation system includes a fuel delivery system that supports fuel, an oxidizer delivery system that supports an oxidizer, a mixer/vaporizer system in fluid communication with the fuel delivery system and the oxidizer delivery system, and a fuel processing reactor system. The mixer/vaporizer system receives the oxidizer from the oxidizer delivery system and the fuel from the fuel delivery system to mix and vaporize the oxidizer and fuel into a first effluent. The fuel processing reactor system receives the first effluent and reacts with the first effluent to generate a second effluent in the form of hot syngas for selective injection into a high speed, air-breathing propulsion system.