A method of reducing noise from a high-speed, including supersonic, jet, the method includes providing the high-speed or supersonic jet in a longitudinal flow direction; and inducing a rotation of a swirl layer of the high-speed or supersonic jet around a longitudinal direction of the jet and on the jet boundary so as to promote mixing of the high-speed or supersonic jet with surrounding air.

In accordance with at least one aspect of this disclosure, a thermoelectric generator (TEG) system can include a TEG conversion element configured to be in thermal communication with a leading edge surface subject to hypersonic flow and a heatsink to generate a temperature differential across the TEG conversion element mounted between the leading edge surface and heatsink, and an electrical conductor configured to connect between the TEG conversion element and a powered unit to supply electrical energy from the TEG conversion element to the powered unit.

A propulsionless munition configured to be launched from a hypersonic aerial includes a munition body that is free of any propulsion system for producing thrust. The munition body includes a forward section including a radome assembly and an aft section including a control system. The radome assembly includes a nose radome and a frangible radome cover disposed over the nose radome for shielding the nose radome from high temperatures resulting from aerodynamic heating at hypersonic speeds. The frangible radome cover is detachable from the nose radome upon detection by the control system of a predetermined threshold comprising at least one of a predetermined speed, a predetermined altitude, and a predetermined temperature.

A propulsionless munition configured to be launched from a hypersonic aerial includes a munition body that is free of any propulsion system for producing thrust. The munition body includes a forward section including a radome assembly and an aft section including a control system. The radome assembly includes a nose radome and a frangible radome cover disposed over the nose radome for shielding the nose radome from high temperatures resulting from aerodynamic heating at hypersonic speeds. The frangible radome cover is detachable from the nose radome upon detection by the control system of a predetermined threshold comprising at least one of a predetermined speed, a predetermined altitude, and a predetermined temperature.

Method and system for global stabilization control of a hypersonic vehicle. The method can include constructing a longitudinal dynamic model of a non-minimum phase hypersonic vehicle; translating a non-zero equilibrium point of the hypersonic vehicle to the origin of coordinates by transformation of coordinates to transform the longitudinal dynamic model, where the transformed longitudinal dynamic model includes an output dynamic model and an internal dynamic model; performing variable decomposition on the transformed longitudinal dynamic model by state decomposition and constructing an auxiliary system model using decomposed variables, where the auxiliary system model includes output dynamics and internal dynamics; and determining a control law based on a feedback linearization theory according to the output dynamics and realizing the global stabilization control of the hypersonic vehicle with the control law. The present disclosure enables the global stabilization control of a non-minimum phase hypersonic vehicle.

A system and method are provided that enable joined materials to expand and contract at different rates while maintaining a structurally sound connection. A system for joining structures with differing coefficients of thermal expansion includes: a first structural element of a first material having a first coefficient of thermal expansion (CTE); a plurality of flexures each defining a first portion and a second portion and attached at the first portion to the first structural element; and a second structural element of a second material having a second CTE, where the second structural element is attached to the second portion of each of the plurality of flexures, where in response to relative movement between the first structural element and the second structural element, the plurality of flexures bend to accommodate the relative movement.

Heat exchangers, heat exchanger systems, and hypersonic vehicles are provided. For example, a heat exchanger is provided that comprises a first chamber for receipt of a flow of cool fluid and a second chamber for receipt of a flow of hot fluid. The heat exchanger further comprises a buffer fluid flowpath for circulation of a buffer fluid therethrough. The buffer fluid circulates within the buffer fluid flowpath disposed between the first chamber and the second chamber to transfer heat from the hot fluid to the cool fluid. In certain embodiments, a hypersonic vehicle comprises such a heat exchanger, and the cool fluid is cryogenic or near-cryogenic fuel of the hypersonic vehicle and the hot fluid is engine bleed air from a hypersonic propulsion engine of the vehicle.

Heat exchangers, heat exchanger systems, and hypersonic vehicles are provided. For example, a heat exchanger is provided that comprises a first chamber for receipt of a flow of cool fluid and a second chamber for receipt of a flow of hot fluid. The heat exchanger further comprises a buffer fluid flowpath for circulation of a buffer fluid therethrough. The buffer fluid circulates within the buffer fluid flowpath disposed between the first chamber and the second chamber to transfer heat from the hot fluid to the cool fluid. In certain embodiments, a hypersonic vehicle comprises such a heat exchanger, and the cool fluid is cryogenic or near-cryogenic fuel of the hypersonic vehicle and the hot fluid is engine bleed air from a hypersonic propulsion engine of the vehicle.

Disclosed are methods, systems, and a non-transitory computer-readable medium for modifying a flight plan of a vehicle. The method may include identifying a maneuver of a flight path that will generate a focus boom, based on received flight path data and permissible threshold boom values for locations along a boom footprint of the maneuver, and generating an adjustment to at least one of a speed, an altitude, an attitude, a location, and a turn radius of the maneuver based on the received data and the permissible threshold boom values. In addition, the method may include updating the flight plan based on the generated adjustment to the at least one of the speed, the altitude, the attitude, the location, and the turn radius of the at least one maneuver.

Disclosed are methods, systems, and a non-transitory computer-readable medium for modifying a flight plan of a vehicle. The method may include identifying a maneuver of a flight path that will generate a focus boom, based on received flight path data and permissible threshold boom values for locations along a boom footprint of the maneuver, and generating an adjustment to at least one of a speed, an altitude, an attitude, a location, and a turn radius of the maneuver based on the received data and the permissible threshold boom values. In addition, the method may include updating the flight plan based on the generated adjustment to the at least one of the speed, the altitude, the attitude, the location, and the turn radius of the at least one maneuver.