Abstract: In accordance with at least one aspect of this disclosure, a method includes flushing a cell stack for a predetermined amount of time as a function of an amount of combustible gas remaining in the cell stack. The method also includes operating a cell stack for a predetermined amount of time, then shutting down the cell stack and ceasing operation of the cell stack for a predetermined amount of time. Flushing occurs after shutting down a cell stack power supply. The method further includes restarting operation of the cell stack after flushing.

Abstract: A power electronic package may comprise a substrate, a semiconductor die bonded to a first surface of the substrate, and an encapsulant deposited over the semiconductor die and substrate. A plurality of encapsulated heat sinks may be dispersed in the encapsulant and/or a plurality of heating pipes may be located in the encapsulant and over an active surface of the semiconductor die.

Abstract: An electronics assembly includes a motor controller electronics arrangement with a solid-state switch array, a feeder cable connected to the motor controller and in electrical communication with the solid-state switch array, and a phase change material body. The phase change material body is thermally coupled to the feeder cable and arranged outside of the motor controller to limit conduction of heat generated by resistive heating of the feeder cable into the motor controller and through the feeder cable. Vehicles, electrical systems, and methods of cooling feeder cables in motor controller electronics arrangements are also described.

Abstract: Disclosed is an assembly including a busbar that includes: a first layer that defines: first layer top and bottom surfaces; first layer first and second ends; and a first layer center region between the first layer first and second ends; and the first layer forms first layer perforations of different sizes about the first layer center region so perforations closer to the first layer first end are smaller than perforations spaced apart therefrom; a second layer that is disposed against and electrically isolated from the first layer bottom surface, wherein the second layer defines connector orifices having a same size as each other that are aligned with the first layer perforations; and a first capacitor supported against and electrically connected to the first layer top surface, wherein the first capacitor includes busbar connectors that respectively extend through the first layer perforations to electrically connect with the connector orifices.

Abstract: An electronics assembly including a motor controller electronics arrangement includes a housing enclosing a solid-state switch array, a cold plate arranged within the housing and in thermal communication with the solid-state switch array, and a feeder cable. The feeder cable is electrically connected to the solid-state switch array, has a coolant jacket extending thereabout, is separated from the switch arrangement by the housing, and is in liquid communication with the cold plate to limit heat communicated by the feeder cable into the housing. Electrical systems and methods of cooling feeder cables are also described.

Abstract: An electronics assembly includes a motor controller electronics arrangement with a solid-state switch array, a feeder cable connected to the motor controller and in electrical communication with the solid-state switch array, and a phase change material body. The phase change material body is thermally coupled to the feeder cable and arranged outside of the motor controller to limit conduction of heat generated by resistive heating of the feeder cable into the motor controller and through the feeder cable. Vehicles, electrical systems, and methods of cooling feeder cables in motor controller electronics arrangements are also described.

Abstract: Disclosed is an assembly including a busbar that includes: a first layer that defines: first layer top and bottom surfaces; first layer first and second ends; and a first layer center region between the first layer first and second ends; and the first layer forms first layer perforations of different sizes about the first layer center region so perforations closer to the first layer first end are smaller than perforations spaced apart therefrom; a second layer that is disposed against and electrically isolated from the first layer bottom surface, wherein the second layer defines connector orifices having a same size as each other that are aligned with the first layer perforations; and a first capacitor supported against and electrically connected to the first layer top surface, wherein the first capacitor includes busbar connectors that respectively extend through the first layer perforations to electrically connect with the connector orifices.

Abstract: A heat transfer tube includes a tube having an internal tube wall, and a tube element extending along a tube length and radially inwardly from the internal tube wall. The tube element has a radial element height less than a hydraulic radius of the tube, and the radial element height is greater than a base element width at the internal tube wall. A tube and shell heat exchanger includes a heat exchanger tube extending through a housing and having a heat transfer medium flowing therethrough. The heat exchanger tube includes a tube having an internal tube wall and tube element extending along a tube length and radially inwardly from the internal tube wall. The tube element has a radial element height less than a hydraulic radius of the tube, and the radial element height is greater than a base element width at the internal tube wall.

Abstract: A system for modulating turbine blade tip clearance is provided. The system may comprise an actuation control system having at least one actuator configured to modulate turbine blade tip clearance between a turbine blade tip and a blade outer air seal (BOAS). Each actuator may be coupled to the BOAS. Each actuator may comprise a solid-state motion amplification device such as a flextensional actuator. The actuators may be configured to move the BOAS in a radial direction from a first position to a second position to control tip clearance.

Abstract: A system for modulating turbine blade tip clearance is provided. The system may comprise an actuation control system having at least one actuator configured to modulate turbine blade tip clearance between a turbine blade tip and a blade outer air seal (BOAS). Each actuator may be coupled to the BOAS. Each actuator may comprise a solid-state motion amplification device such as a flextensional actuator. The actuators may be configured to move the BOAS in a radial direction from a first position to a second position to control tip clearance.

Abstract: A heat exchange system may include a first heat exchange circuit and a second heat exchange circuit. The first heat exchange circuit may circulate a first working fluid sequentially through a first heat exchanger, a second heat exchanger and a membrane contactor. The second heat exchange circuit may direct a second working fluid sequentially through the first heat exchanger and the membrane contactor, where the second working fluid includes solute and solvent. The first heat exchanger and the membrane contactor may transfer heat energy from the second working fluid to the first working fluid, and the second heat exchanger may transfer heat energy from the first working fluid to a third working fluid. The membrane contactor may extract a portion of the solvent from the second working fluid.

Abstract: A heat exchange system may include a first heat exchange circuit and a second heat exchange circuit. The first heat exchange circuit may circulate a first working fluid sequentially through a first heat exchanger, a second heat exchanger and a membrane contactor. The second heat exchange circuit may direct a second working fluid sequentially through the first heat exchanger and the membrane contactor, where the second working fluid includes solute and solvent. The first heat exchanger and the membrane contactor may transfer heat energy from the second working fluid to the first working fluid, and the second heat exchanger may transfer heat energy from the first working fluid to a third working fluid. The membrane contactor may extract a portion of the solvent from the second working fluid.

Abstract: The invention involves a flat fin heat exchanger configuration 10 with a plurality of louvers 26 that are raised above the plane of the fin 16 between adjacent tube holes 19, 20 that receive tubes 14. Various alternative patterns of louvers enhance the heat transfer characteristics of the fin, and allow for the use of thinner materials to lower cost without diminishing performance. The exterior fin surface redirects air flow from the leading edge to the trailing edge of the fin. This effect directs the air flow over and in between the interrupted surfaces, thus breaking up air boundary layer around the fin. The louvers of the fin are oriented relative to the air flow in such a manner that each louver in effect creates another leading edge, thus contributing to a higher heat transfer coefficient.

Abstract: A spirally wound tube heat exchanger 10 article that receives a heat exchange fluid and its method of manufacture. In one embodiment, the exchanger 10 has one or more spirally-wound layers 12 of a tube 14. In some embodiments, the layers are circular, oval or rectangular with radiused corners. An elongate spacer member 24 has forwardly 26 and rearwardly 28 facing edges. Defined within those edges are engagement surfaces 30 that detachably retain the tube 14.

Abstract: The invention involves a flat fin heat exchanger configuration 10 with a plurality of louvers 26 that are raised above the plane of the fin 16 between adjacent tube holes 19, 20 that receive tubes 14. Various alternative patterns of louvers enhance the heat transfer characteristics of the fin, and allow for the use of thinner materials to lower cost without diminishing performance. The exterior fin surface redirects air flow from the leading edge to the trailing edge of the fin. This effect directs the air flow over and in between the interrupted surfaces, thus breaking up air boundary layer around the fin. The louvers of the fin are oriented relative to the air flow in such a manner that each louver in effect creates another leading edge, thus contributing to a higher heat transfer coefficient.

Abstract: A spirally wound tube heat exchanger 10 article that receives a heat exchange fluid and its method of manufacture. In one embodiment, the exchanger 10 has one or more spirally-wound layers 12 of a tube 14. In some embodiments, the layers are circular, oval or rectangular with radiused corners. An elongate spacer member 24 has forwardly 26 and rearwardly 28 facing edges. Defined within those edges are engagement surfaces 30 that detachably retain the tube 14.