Abstract: A heat exchanger includes a body, a plurality of first flow channels defined in the body; and a plurality of second flow channels defined in the body. The second flow channels are fluidly isolated from the first flow channels. The first flow channels and second flow channels are arranged in a checkerboard pattern.

Abstract: A heat transfer system (e.g., a heat pump) can include at least a first fin array and at least a first pump disposed in fluid communication with the first fin array and configured to cause a first fluid to flow through the first fin array. The system can include at least a first heat transfer layer attached to and/or in thermal communication with the first fin array. The first heat transfer layer can define a second fluid flow path therein for a second fluid to flow fluidly isolated from the first fluid. The first heat transfer layer and the first fin array can be configured to cause heat transfer between the first fluid and the second fluid.

Abstract: A heat exchanger arrangement includes walls defining at least two circuit passages for porting a first fluid, a first of the circuit passages defining a first passage length, and a second of the circuit passages defining a second passage length, the second passage length being different from the first passage length, the walls being in thermal communication with a second fluid while isolating the first fluid from the second fluid, at least one of the first circuit passage and the second circuit passage includes a flow control feature configured to decrease an imbalance in flow between the first circuit passage and the second circuit passage compared to if the flow control feature were not present.

Abstract: An environmental control system includes a refrigerant circuit with a pump segment and an evaporator segment, an evaporator arranged along the evaporator segment and in fluid communication with of the refrigerant circuit, and a coolant circuit. The coolant circuit extends through the evaporator and is thermally coupled to refrigerant circuit by the evaporator, the coolant circuit including a first segment and a second segment arranged in parallel with one another to transfer heat from a first zone to a first portion of liquid coolant traversing the coolant circuit and transfer additional heat from a second zone to a second portion of coolant traversing the coolant circuit. Aircraft and environmental control systems are also described.

Abstract: Provided are embodiments for a system for offloading non-thrust loads. The system includes one or more thrust loads, and one or more non-thrust loads, and a controller that is operably coupled to the one or more thrust loads and the one or more non-thrust loads. The controller is configured to control the thrust loads and non-thrust loads, receive input from one or more sources, and identify a phase of flight based at least in part on the received input. The controller is also configured to offload one or more non-thrust loads during the phase of flight, and restore the one or more non-thrust loads. Also provided are embodiments for method for offloading non-thrust loads.

Abstract: A light assembly may comprise: a light array comprising a plurality of light emitting diodes (LEDs), each light emitting diode (LED) configured to emit an electromagnetic radiation having a wavelength, the wavelength of each LED being different, a first LED in the light array configured to emit a first wavelength between 414 nm and 474 nm; and a non-linear optical layer disposed adjacent to the first LED, the nonlinear optical layer configured to output the first wavelength and a second wavelength, the second wavelength being between 207 nm and 237 nm.

Abstract: A system and method for enhancing a diffusion limited CVI/CVD process is provided. The system may densify a porous structure by flowing a reactant gas around the porous structure. A mass flow controller may be configured to pulse the flow rate of the reactant gas around the porous structure. The mass flow controller may pulse the flow rate from a nominal flow rate to a first flow rate. The mass flow controller may pulse the first flow rate back to the nominal flow rate or to a second flow rate. The mass flow controller may pulse the flow rate between the nominal flow rate, the first flow rate, and the second flow rate, as desired.

Abstract: A hand drying system for an aircraft lavatory includes a hand blower tap with an inlet configured to connect to an aircraft environmental control system (ECS) to receive a flow of conditioned air from the ECS. A valve is operatively connected to the inlet to selectively block flow from the ECS and allow flow from the ECS through the hand blower tap.

Abstract: An apparatus for modular AC to AC frequency conversion is disclosed. An input AC source is configured to generate an input AC voltage at a first frequency. At least one primary low frequency (LF) conversion stage is configured to generate a DC voltage, and comprises a first pair of metal-oxide-semiconductor field effect transistors (MOSFETs). At least one primary high frequency (HF) conversion stage is configured to generate the DC voltage, and comprises a first pair of high electron mobility transistors (HEMTs). At least one secondary LF conversion stage is configured to receive the DC voltage and generate an output AC voltage at a second frequency, and comprises a second pair of MOSFETs. At least one secondary HF conversion stage is configured to receive the DC voltage and generate the output AC voltage at the second frequency, and comprises a second pair of HEMTs.

Abstract: A power converter includes an amplifier, an inductor, a capacitor, and an interconnection block formed of an insulating material having conductive material deposited thereon by a multi-material printing process. The interconnection block supports one of the inductor and the capacitor in a manner that the one the inductor and the capacitor is disposed vertically above an other of the inductor and the capacitor.

Abstract: An environmental control system that includes a first environmental control system pack, a first recirculation fan assembly, and a cabin air sensor unit. The first environmental control system pack is arranged to provide conditioned air to an aircraft cabin. The first recirculation fan assembly is arranged to recirculate a first cabin air fluid flow back to the aircraft cabin. The cabin air sensor unit is arranged to provide a first air quality signal indicative of an air quality of the first cabin air fluid flow to a controller.

Abstract: System and methods for power conversion are provided. Aspects include a first switching module comprising a first set of switches, wherein the first set of switches comprise wide-bandgap devices having a first bandgap, a second switching module comprising a second set of switches, wherein the second set of switches comprise semiconductor devices having a second bandgap, and wherein the first bandgap is larger than the second bandgap, an alternating current (AC) power source connected to the first switching module and the second switching module, a first capacitor bank, a second capacitor bank, and a controller configured to operate the first switching module and the second switching module to create a first direct current (DC) voltage across the first capacitor bank and a second direct current (DC) voltage across the second capacitor bank.

Abstract: A header duct and method of forming a header duct includes an inlet portion having a planar inlet, an outlet portion have a plurality of planar outlets, and a transition portion extending continuously from the inlet portion to the outlet portion. The transition portion has a bend and internal topography defining a non-monotonic cross-sectional area distribution between the inlet and outlet portions. The transition portion can further include a bulbous region extending in a lateral direction of the duct and a protrusion located along an inside radius of the bend.

Abstract: A heat exchanger arrangement includes walls defining at least two circuit passages for porting a first fluid, a first of the circuit passages defining a first passage length, and a second of the circuit passages defining a second passage length, the second passage length being different from the first passage length, the walls being in thermal communication with a second fluid while isolating the first fluid from the second fluid, at least one of the first circuit passage and the second circuit passage includes a flow control feature configured to decrease an imbalance in flow between the first circuit passage and the second circuit passage compared to if the flow control feature were not present.

Abstract: Devices, systems, methods, and articles of manufacture for delivering disinfecting electromagnetic radiation to various areas, items, and components of a cabin of an aircraft are provided herein. For example, the disclosed disinfecting system may be configured to emit electromagnetic radiation to disinfect a stowable item, such as a personal item of a passenger or a component of the aircraft cabin. Generally, the devices, systems, methods, and articles of manufacture disclosed and described herein facilitate disinfection treatments, especially to items and/or components that would not be subjected to conventional aircraft cleaning treatments.

Abstract: A counterflow heat exchanger configured to exchange heat between a first fluid flow at a first pressure and a second fluid flow at a second pressure includes a first fluid inlet, a first fluid outlet fluidly coupled to the first fluid inlet via a core section, a second fluid inlet, and a second fluid outlet fluidly coupled to the second fluid inlet via the core section. The core section includes a plurality of first fluid passages configured to convey the first fluid flow from the first fluid inlet toward the first fluid outlet, and a plurality of second fluid passages configured to convey the second fluid flow from the second fluid inlet toward the second fluid outlet such that the first fluid flow exchanges thermal energy with the second fluid flow at the core section. Each first fluid passage of the plurality of first fluid passages has a circular cross-section.

Abstract: System and methods for power conversion are provided. Aspects include a first switching module comprising a first set of switches, wherein the first set of switches comprise wide-bandgap devices having a first bandgap, a second switching module comprising a second set of switches, wherein the second set of switches comprise semiconductor devices having a second bandgap, and wherein the first bandgap is larger than the second bandgap, an alternating current (AC) power source connected to the first switching module and the second switching module, a first capacitor bank, a second capacitor bank, and a controller configured to operate the first switching module and the second switching module to create a first direct current (DC) voltage across the first capacitor bank and a second direct current (DC) voltage across the second capacitor bank.

Abstract: A heat exchanger includes a plate with an external surface, a channel, and a nozzle. The external surface bounds an interior of the plate. The channel is disposed in the heat exchanger and passes through a portion of the interior. The nozzle is integrally disposed in the heat exchanger, extends through a portion of the external surface, and is fluidly connected to the channel. The nozzle is configured to transport a liquid from the channel, through the external surface, and to distribute the liquid onto a portion of the heat exchanger.

Abstract: A method for collecting an aircraft cabin representative biological sample from an aircraft HEPA (high efficiency particulate air) filter including collecting a used HEPA filter after flight, transferring the HEPA filter to a remote location, processing the HEPA filter in order to remove an air sample, and concentrating the collected sample to be used on a pathogen identifying tester.

Abstract: A system for collecting a biological sample from a passenger cabin includes a collector for collecting particulate samples positioned within at least one of a passenger cabin or a cabin air outflow flow path. A method for collecting particulates from cabin air includes capturing particulates in at least one of a passenger cabin or a cabin air outflow flow path with a collector for a period of time. The method includes removing the collector from at least one of the passenger cabin or air outflow flow path for testing. The method includes placing a clean collector into at least one of the passenger cabin or a cabin air outflow flow path for use during another period of time.