Abstract: A vapor-compression system includes a centrifugal compressor configured to increase a pressure of a refrigerant based on at least one of an activation of a device or the device being equal to or above a first threshold temperature. A fluid communication system is configured to provide, to the device, a portion of the refrigerant in a liquid state. The portion of the liquid refrigerant in a liquid state is configured to have a saturation temperature equal to or below the first temperature threshold.

Abstract: In some examples, the disclosure describes a method including densifying a layer of carbon fibers by at least one of depositing a resin on the layer of carbon fibers via a print head of a three-dimensional printing system or applying CVD on the layer of carbon fibers via the print head; and forming at least one additional layer of densified carbon fibers on the densified layer of carbon fibers, wherein forming the at least one additional layer of densified carbon fibers comprises, for each respective layer of the at least one additional layer, adding an additional layer of carbon fibers on the densified layer of carbon fibers, and densifying the additional layer of carbon fibers by at least one of depositing the resin on the additional layer of carbon fibers or applying CVD on the additional layer of carbon fibers. In some examples, the example method may be used to form a densified carbon-carbon composite component, such as, e.g., a densified carbon-carbon composite brake disc.

Abstract: In some examples, the disclosure describes a method including depositing a first layer including a resin and at least one of a carbon fiber or a carbon fiber precursor material on a work surface of a three-dimensional printing system, carbonizing at least the resin of the first layer using a carbonizer attached to the three-dimensional printer to form a first layer of carbon-carbon composite including carbon fibers and carbonized matrix material, depositing an additional layer including a resin and at least one of a carbon fiber or a carbon fiber precursor material of material on the first layer of carbon-carbon composite, and carbonizing at least the resin of the additional layer using the carbonizer to form an additional layer of carbon-carbon composite on the first layer of carbon-carbon composite.

Abstract: In some examples, a method for forming a carbon fiber preform includes depositing, via a print head of a three-dimensional printing system, a first plurality of carbon fibers to form a first layer of carbon fibers in approximately an x-y plane, wherein the first plurality of carbon fibers are deposited around an array of carbon fiber filaments extending in approximately a z-axis direction relative to the x-y plane.

Abstract: In some examples, the disclosure describes a method including depositing a first layer including a resin and at least one of a carbon fiber or a carbon fiber precursor material on a work surface of a three-dimensional printing system, carbonizing at least the resin of the first layer using a carbonizer attached to the three-dimensional printer to form a first layer of carbon-carbon composite including carbon fibers and carbonized matrix material, depositing an additional layer including a resin and at least one of a carbon fiber or a carbon fiber precursor material of material on the first layer of carbon-carbon composite, and carbonizing at least the resin of the additional layer using the carbonizer to form an additional layer of carbon-carbon composite on the first layer of carbon-carbon composite.

Abstract: A brake monitoring system comprises a wear pin that is operatively connected to a brake to be monitored, wherein the wear pin can translate along a longitudinal axis of the wear pin and not rotate about the longitudinal axis; a wear gear rotationally affixed to the wear pin to enable the wear gear to rotate as the wear pin translates; and a counting device operatively adjacent the wear gear, wherein the counting device measures one of an amount of rotation of the wear gear and a rate of rotation of the wear gear.

Abstract: In some examples, a method for forming a carbon fiber preform includes depositing, via a print head of a three-dimensional printing system, a first plurality of carbon fibers to form a first layer of carbon fibers in approximately an x-y plane, wherein the first plurality of carbon fibers are deposited around an array of carbon fiber filaments extending in approximately a z-axis direction relative to the x-y plane.

Abstract: In some examples, the disclosure describes a method including densifying a layer of carbon fibers by at least one of depositing a resin on the layer of carbon fibers via a print head of a three-dimensional printing system or applying CVD on the layer of carbon fibers via the print head; and forming at least one additional layer of densified carbon fibers on the densified layer of carbon fibers, wherein forming the at least one additional layer of densified carbon fibers comprises, for each respective layer of the at least one additional layer, adding an additional layer of carbon fibers on the densified layer of carbon fibers, and densifying the additional layer of carbon fibers by at least one of depositing the resin on the additional layer of carbon fibers or applying CVD on the additional layer of carbon fibers. In some examples, the example method may be used to form a densified carbon-carbon composite component, such as, e.g., a densified carbon-carbon composite brake disc.

Abstract: A brake monitoring system comprises a wear pin that is operatively connected to a brake to be monitored, wherein the wear pin can translate along a longitudinal axis of the wear pin and not rotate about the longitudinal axis; a wear gear rotationally affixed to the wear pin to enable the wear gear to rotate as the wear pin translates; and a counting device operatively adjacent the wear gear, wherein the counting device measures one of an amount of rotation of the wear gear and a rate of rotation of the wear gear.