Abstract: Example split valves for regulating a first flowrate and a second flowrate of a fluid within a closed loop systems are disclosed herein. An example split valve includes an electrohydraulic servo valve coupled to a first piston via a first hydraulic flowline and a second hydraulic flowline, the first piston to include a piston shaft, a first head, and a second head; one or more bellows fixed to at least one of the first head or the second head, the one or more bellows to hermetically seal the fluid from a hydraulic fluid; and a control system connected to the electrohydraulic servo valve, the control system to adjust the first flowrate and the second flowrate of the fluid through a first fluid chamber, the first piston to be located in the first fluid chamber.

Abstract: Airfoil include a body extending along a spanwise direction between a root end and a tip end, the body comprising a plurality of acoustic cavities each having an inlet on the airfoil; and at least one cooling channel having an inlet section an outlet section and a middle section within the airfoil extending between the inlet section and the outlet section; and at least one porous face sheet positioned on at least one inlet of the plurality of acoustic cavities.

Abstract: A cooling system includes a conduit extending from an upstream end to a downstream end and retains a gas. A heat exchanger is fluidly coupled with and disposed within a surface of the conduit. A portion of the gas is directed into the heat exchanger via one or more passages extending between the conduit and the heat exchanger, and a portion of the gas is directed out of the heat exchanger via the one or more passages. The heat exchanger directs cooling fluid in one or more directions within the heat exchanger along one or more passageways of plural passageways. The heat exchanger directs the portion of the gas in one or more directions within the heat exchanger along one or more other passageways of the plural passageways. The heat exchanger cools the gas by exchanging heat from the gas to the cooling fluid within the heat exchanger.

Abstract: A thermal structure for management of thermal energy, the thermal structure including: a first wall structure defining a first cavity; a second wall structure defining a second cavity, the second cavity in fluid communication with the first cavity; and a barrier cavity defined at least in-part by the first wall structure and the second wall structure, wherein the barrier cavity is disposed between the first cavity and the second cavity and includes a pressurized barrier fluid therein or is configured to receive the pressurized barrier fluid during operation of the thermal structure.

Abstract: A heat exchanger is provided that can include furcating unit cells coupled with each other. Each of the unit cells can be elongated along an axis and include a sidewall that defines annular ring openings on opposite ends of the unit cell along the axis. The sidewall also can define undulating annular rings between the annular ring openings and axially separated from each other along the axis. The sidewall can further define angled openings into the unit cell both above and below each of the undulating annular rings. At least a first opening of the annular ring openings and the angled openings can be configured to be an inlet to receive a first fluid into the unit cell and at least a second opening of the annular ring openings and the angled openings configured to be an outlet through which the first fluid exits the unit cell.

Abstract: A system for heat exchange and leak detection is generally provided, the system including a heat exchanger including a first wall defining a first passage containing a first fluid. A leak detection enclosure containing a leak detection medium is defined between the first wall and a second wall surrounding the first wall.

Abstract: A heat exchanger includes a core defining a first passageway for a first fluid flow and a second passageway for a second fluid flow. The core includes an assembly of a plurality of unit cells coupled together. Each unit cell defines a first passageway portion within an interior volume and a second passageway portion at an exterior surface. Each unit cell includes a plurality of first openings into the interior volume and forms the second passageway in volumes between the plurality of unit cells. The assembly is shaped to combine and divide the first fluid in the first passageway portion and combine and divide the second fluid in the second passageway portion during exchange of heat between the first fluid and the second fluid. Each second passageway portion receives the second fluid from three other second passageway portions.

Abstract: A heat exchanger is provided that can include furcating unit cells coupled with each other. Each of the unit cells can be elongated along an axis and include a sidewall that defines annular ring openings on opposite ends of the unit cell along the axis. The sidewall also can define undulating annular rings between the annular ring openings and axially separated from each other along the axis. The sidewall can further define angled openings into the unit cell both above and below each of the undulating annular rings. At least a first opening of the annular ring openings and the angled openings can be configured to be an inlet to receive a first fluid into the unit cell and at least a second opening of the annular ring openings and the angled openings configured to be an outlet through which the first fluid exits the unit cell.

Abstract: The present disclosure pertains to electric machines such as electric propulsion systems for aircraft that integrated cooling systems, and methods of cooling such an electric machine. Exemplary electric machines include an electric motor that has a stator, a rotor, and a drive shaft operably coupled to the rotor. Exemplary electric machines further include a motor cooling conduit that defines a pathway for conveying a cooling fluid through or around at least a portion of the electric motor, a casing assembly that circumferentially surrounds at least a portion of the electric motor, a casing assembly conduit integrally formed within at least a portion of the casing assembly which defines a pathway for conveying the cooling fluid through the at least a portion of the casing assembly, and a pump or compressor operably coupled to the drive shaft and configured to circulate the cooling fluid through the motor cooling conduit and the casing assembly conduit.

Abstract: A counter-flow heat exchanger including a core region and a plenum region. The core region including a first set of heat exchanging passageways and a second set of heat exchanging passageways disposed at least partially therein. A plenum region is disposed adjacent opposed distal ends of the core region. Each of the plenum regions including a fluid inlet plenum, a fluid outlet plenum and a tube plate disposed therebetween. The first set of heat exchanging passageways is truncated and defines a first tube-side fluid flow path in a first direction. The second set of heat exchanging passageways defines a second tube-side fluid flow path in a second opposing direction. Each of the heat exchanging passageways extending from a fluid inlet plenum to a fluid outlet plenum. The tube plates and the core region include one of a cast metal formed thereabout each of the heat exchanging passageways or a braze bond formed between each of the heat exchanging passageways.

Abstract: An aerospace vehicle including: a body, wherein the body is configured to generate heat during operation; a coating disposed over at least a portion of the body, the coating being configured to shift a frequency of at least one wavelength of the heat generated by the body from a first frequency to a second frequency having higher transmissivity relative to a neighboring medium surrounding the body as compared to the first frequency.

Abstract: A heat exchanger is provided. The heat exchanger provides a first plurality of tubes and a second plurality of flow passages which furcate near one of the first and second manifolds into two or more furcated flow passages and subsequently converge to exit the heat exchanger. The plurality of furcated flow passages are intertwined, reducing the distance between flow passages containing each fluid therebetween to improve thermal transfer. Further, the furcations create changes of direction of the fluid to re-establish new thermal boundary layers within the flow passages to further reduce resistance to thermal transfer.

Abstract: Example split valves for regulating a first flowrate and a second flowrate of a fluid within a closed loop systems are disclosed herein. An example split valve includes an electrohydraulic servo valve coupled to a first piston via a first hydraulic flowline and a second hydraulic flowline, the first piston to include a piston shaft, a first head, and a second head; one or more bellows fixed to at least one of the first head or the second head, the one or more bellows to hermetically seal the fluid from a hydraulic fluid; and a control system connected to the electrohydraulic servo valve, the control system to adjust the first flowrate and the second flowrate of the fluid through a first fluid chamber, the first piston to be located in the first fluid chamber.

Abstract: A heat exchange module, a heat exchanger and a method for additively manufacturing the heat exchanger are provided. The heat exchanger includes a plurality of stacked heat exchange modules defining a flow passageway. Each heat exchange module defining a substantially curved closed geometry defining a central axis that extends along the axial direction. Each heat exchange module includes a first heat exchanging fluid inlet, a first heat exchanging fluid outlet and a plurality of heat exchange tubes fluidly coupling the first heat exchanging fluid inlet and the first heat exchanging fluid outlet. The plurality of heat exchange tubes defining a plurality of first heat exchanging fluid flow passages of equal length and a plurality of second heat exchanging fluid flow passages of equal hydraulic diameter.

Abstract: A thermal structure for management of thermal energy, the thermal structure including: a first wall structure defining a first cavity; a second wall structure defining a second cavity, the second cavity in fluid communication with the first cavity; and a barrier cavity defined at least in-part by the first wall structure and the second wall structure, wherein the barrier cavity is disposed between the first cavity and the second cavity and includes a pressurized barrier fluid therein or is configured to receive the pressurized barrier fluid during operation of the thermal structure.

Abstract: A thermal management system for transferring heat between fluids includes a thermal transport bus through which a heat exchange fluid flows. Additionally, the system includes a heat source heat exchanger arranged along the bus such that heat is added to the fluid flowing through the heat source heat exchanger. Moreover, the system includes a plurality of heat sink heat exchangers arranged along the bus such that heat is removed from the fluid flowing through the plurality of heat sink heat exchangers. Furthermore, the system includes a bypass conduit fluidly coupled to the bus such that the bypass conduit allows the fluid to bypass one of the heat source heat exchanger or one of the heat sink heat exchangers. In addition, the system includes a valve configured to control a flow of the fluid through the bypass conduit based on a pressure of the fluid within the bus.

Abstract: A cyclone cooler device includes a housing that defines an interior channel elongated along a center axis. One or more of the fluid passage or configuration of an inlet end of the channel is shaped to induce a swirling flow of a cooling fluid within the channel while the channel is thermally coupled with one or more heat sources. The swirling flow of the cooling fluid removes thermal energy from and cools the one or more heat sources. During the swirling flow, the cooling fluid rotates around the center axis of the channel while also moving along the length of the center axis. The cooling fluid changes phases during the swirling flow to cool the heat source(s).

Abstract: A heat exchange module, a heat exchanger and a method for additively manufacturing the heat exchanger are provided. The heat exchanger includes a plurality of stacked heat exchange modules defining a flow passageway. Each heat exchange module defining a substantially curved closed geometry defining a central axis that extends along the axial direction. Each heat exchange module includes a first heat exchanging fluid inlet, a first heat exchanging fluid outlet and a plurality of heat exchange tubes fluidly coupling the first heat exchanging fluid inlet and the first heat exchanging fluid outlet. The plurality of heat exchange tubes defining a plurality of first heat exchanging fluid flow passages of equal length and a plurality of second heat exchanging fluid flow passages of equal hydraulic diameter.

Abstract: A thermal management system for transferring heat between fluids includes a thermal transport bus through which a heat exchange fluid flows. Additionally, the system includes a heat source heat exchanger arranged along the bus such that heat is added to the fluid flowing through the heat source heat exchanger. Moreover, the system includes a plurality of heat sink heat exchangers arranged along the bus such that heat is removed from the fluid flowing through the plurality of heat sink heat exchangers. Furthermore, the system includes a bypass conduit fluidly coupled to the bus such that the bypass conduit allows the fluid to bypass one of the heat source heat exchanger or one of the heat sink heat exchangers. In addition, the system includes a valve configured to control a flow of the fluid through the bypass conduit based on a pressure of the fluid within the bus.

Abstract: An aerospace vehicle including: a body, wherein the body is configured to generate heat during operation; a coating disposed over at least a portion of the body, the coating being configured to shift a frequency of at least one wavelength of the heat generated by the body from a first frequency to a second frequency having higher transmissivity relative to a neighboring medium surrounding the body as compared to the first frequency.