Structural subsurface materials and subsurface structures adapted for interacting with a flow are provided. In one example, a structural subsurface material or subsurface structure is provided for use in interacting with a fluid or solid flow. The structural subsurface material comprises a flow interface surface adapted to be disposed adjacent a flow and a subsurface feature comprising a structural material. The subsurface feature extends away from the flow interface surface. The subsurface feature alters an effective structural compliance of the flow interface surface relative to the flow such that the flow experiences an alteration in surface skin-friction drag and/or in kinetic energy in a turbulent flow. In other implementations, methods of controlling a flow with a structural subsurface material or a subsurface structure are provided. Further, methods of designing structural subsurface materials and subsurface structures for interacting with a flow are also provided.

A system that optimizes the shape or configuration of an aircraft to minimize ground overpressure shock strength while in supersonic flight over speed restricted terrain and to morph to an optimized configuration for drag minimization while over unrestricted terrain.

A system that optimizes the shape or configuration of an aircraft to minimize ground overpressure shock strength while in supersonic flight over speed restricted terrain and to morph to an optimized configuration for drag minimization while over unrestricted terrain.

A hypersonic aircraft includes one or more leading edge assemblies that are designed to manage thermal loads experienced at the leading edges during high speed or hypersonic operation. Specifically, the leading edge assemblies may include an outer wall tapered to a leading edge or stagnation point. The outer wall may define a vapor chamber and a capillary structure within the vapor chamber for circulating a working fluid in either liquid or vapor form to cool the leading edge. In addition, a dual-modal cooling structure can enhance heat transfer from the outer wall at the leading edge to the outer wall within the condenser section of the vapor chamber.

A hypersonic aircraft includes one or more leading edge assemblies that are designed to manage thermal loads experienced at the leading edges during high speed or hypersonic operation. Specifically, the leading edge assemblies may include an outer wall tapered to a leading edge or stagnation point. The outer wall may define a vapor chamber and a capillary structure within the vapor chamber for circulating a working fluid in either liquid or vapor form to cool the leading edge. In addition, a dual-modal cooling structure can enhance heat transfer from the outer wall at the leading edge to the outer wall within the condenser section of the vapor chamber.

A single unducted rotor engine includes a power source; a casing surrounding the power source; an unducted rotor assembly driven by the power source having a single row of rotor blades; and an outlet guide vane assembly having a plurality of pairs of outlet guide vanes, each pair of the plurality of pairs of outlet guide vanes including a first outlet guide vane extending from the casing at a location downstream from the single row of rotor blades of the unducted rotor assembly and a second outlet guide vane also positioned downstream from the single row of rotor blades of the unducted rotor assembly. The first outlet guide vane of each pair of outlet guide vanes defines a first geometry. The second outlet guide vane of each pair of outlet guide vanes defines a second geometry. The first geometry is not equal to the second geometry.

A single unducted rotor engine includes a power source; a casing surrounding the power source; an unducted rotor assembly driven by the power source having a single row of rotor blades; and an outlet guide vane assembly having a plurality of pairs of outlet guide vanes, each pair of the plurality of pairs of outlet guide vanes including a first outlet guide vane extending from the casing at a location downstream from the single row of rotor blades of the unducted rotor assembly and a second outlet guide vane also positioned downstream from the single row of rotor blades of the unducted rotor assembly. The first outlet guide vane of each pair of outlet guide vanes defines a first geometry. The second outlet guide vane of each pair of outlet guide vanes defines a second geometry. The first geometry is not equal to the second geometry.

A nonintegral cold plate is described for providing cooling of battery charging. The nonintegrated cold plate can receive and circulate coolant against a surface of a battery or of a vehicle. After charging the nonintegrated cold plate can be removed to save weight on the vehicle's payload.

A nonintegral cold plate is described for providing cooling of battery charging. The nonintegrated cold plate can receive and circulate coolant against a surface of a battery or of a vehicle. After charging the nonintegrated cold plate can be removed to save weight on the vehicle's payload.

Methods and apparatus for cooling a surface on a flight vehicle and generating power include advancing the vehicle at a speed of at least Mach 3 to aerodynamically heat the surface. A first working fluid circulates through a first fluid loop that heats the first working fluid through a first heat intake thermally coupled to the surface and expands the first working fluid in a first thermal engine to generate a first work output. A second fluid loop has a second working fluid that receives heat from the first working fluid and a second thermal engine to generate a second work output. The first and second work outputs are operably coupled to first and second generators, respectively, to power primary or auxiliary systems on the flight vehicle.