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.

A heat exchanger which may be used in an engine, such as a vehicle engine for an aircraft or orbital launch vehicle. is provided. The heat exchanger may be configured as generally drum-shaped with a multitude of spiral sections, each containing numerous small diameter tubes. The spiral sections may spiral inside one another. The heat exchanger may include a support structure with a plurality of mutually axially spaced hoop supports, and may incorporate an intermediate header. The heat exchanger may incorporate recycling of methanol or other antifreeze used to prevent blocking of the heat exchanger due to frost or ice formation.

A hybrid airbreathing rocket engine module (70) comprises an air intake arrangement (62) configured to receive air and a heat exchanger arrangement (63) configured to cool air from the air intake arrangement (62); a compressor (64) configured to compress air from the heat exchanger arrangement (63); and one or more thrust chambers (65). The air intake arrangement (62), the compressor (64), the heat exchanger arrangement (63), and the one or more thrust chambers (65) are arranged generally along an axis (69) of the engine module (70). The heat exchanger arrangement (63) is arranged between the compressor (64) and the one or more thrust chambers (65).

A method of designing a morphable aerodynamic surface includes discretizing and parameterizing a model of a morphable surface to create a function to optimize; utilizing finite element analysis to solve for displacements and associated errors at an initialization point; and iteratively calculating a gradient cost function, define step size and search direction, step according to defined step size and search direction, and recalculate displacements and associated errors to converge on final thickness vector.

A method of designing a morphable aerodynamic surface includes discretizing and parameterizing a model of a morphable surface to create a function to optimize; utilizing finite element analysis to solve for displacements and associated errors at an initialization point; and iteratively calculating a gradient cost function, define step size and search direction, step according to defined step size and search direction, and recalculate displacements and associated errors to converge on final thickness vector.

Lobed mixer nozzles for supersonic and subsonic aircraft, and associated systems and methods are disclosed herein. A representative lobe mixer nozzle includes a fan flow duct aligned along a longitudinal axis, and a core flow duct, also aligned along the longitudinal axis. At least one duct wall, for example, a splitter, forms, at least in part, a radially inner boundary of the fan flow duct, and a radially outer boundary of the core flow duct. The duct wall terminates at a reference exit plane, and has multiple first lobes extending radially inwardly, and multiple second lobes extending radially outwardly. At least one lobe is canted forward relative to the reference exit plane, and at least one lobe is canted aft relative to the reference exit plane.

Lobed mixer nozzles for supersonic and subsonic aircraft, and associated systems and methods are disclosed herein. A representative lobe mixer nozzle includes a fan flow duct aligned along a longitudinal axis, and a core flow duct, also aligned along the longitudinal axis. At least one duct wall, for example, a splitter, forms, at least in part, a radially inner boundary of the fan flow duct, and a radially outer boundary of the core flow duct. The duct wall terminates at a reference exit plane, and has multiple first lobes extending radially inwardly, and multiple second lobes extending radially outwardly. At least one lobe is canted forward relative to the reference exit plane, and at least one lobe is canted aft relative to the reference exit plane.

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.

Dissimilarly shaped aircraft nozzles with tandem mixing devices, and associated systems and methods are disclosed. An ejector nozzle in a representative embodiment includes a nozzle duct having a nozzle flow axis, a first axial position and a second axial position. The nozzle duct has a first cross-sectional shape at the first axial position, and a second cross-sectional shape at the second axial position, with the second shape being geometrically non-similar to the first shape. The nozzle further includes a fan flow duct portion and a core flow duct portion, both upstream of the first axial position. An ejector duct is positioned in fluid communication with the nozzle duct, and has at least one portion with a cross-sectional shape geometrically similar to the second cross-sectional shape. A first mixing device is positioned proximate to the first axial position to mix fan flow in the fan flow duct portion with core flow in the core flow duct portion, and a second mixing device is positioned downstream of the first mixing device to mix the fan flow and the core flow with flow through the ejector duct, and direct the combined flow generally along the nozzle flow axis. A representative design technique can include selecting an axial position for, and tailoring the shape of, the second mixing device, such as, their spanwise spacings, to enhance flow characteristics of interest, e.g., identified via computational fluid dynamic techniques, that may appear at (e.g., only at) a downstream position.