Abstract: A gas turbine engine apparatus includes a variable vane. The variable vane includes a pivot axis and an airfoil. The variable vane is configured to pivot about the pivot axis between a first position and a second position. The airfoil extends spanwise along a span line between a first end and a second end. The airfoil extends chordwise along a chord line between a leading edge and a trailing edge. The chord line is angularly offset from a reference plane containing the pivot axis by a twist angle. A first section of the airfoil is disposed at the first end. The twist angle varies as the first section extends spanwise along the span line. A second section of the airfoil is disposed spanwise between the first section and the second end. The twist angle is uniform as the second section extends spanwise along the span line.

Abstract: An air intake plenum for a gas turbine engine is provided that includes an axial centerline, first and second gas path surfaces, and a plurality of struts. The gas path surfaces are spaced apart from one another and define at least a portion of a plenum interior. The struts extend lengthwise between the gas path surfaces. Each strut has a cross-section geometry. The cross-section geometry has a center, and major and minor axes. The struts are circumferentially spaced apart from one another within the plenum. Each strut is oriented at a clocking angle theta. The clocking angle theta for each respective strut is disposed between the major axis of that strut and a line that intersects the cross-section geometry center of that strut and the axial centerline. At least one strut of the plurality of struts is oriented at a clocking angle theta that is greater than zero.

Abstract: A gas turbine engine apparatus includes an engine flowpath, a protuberance and a variable vane. The protuberance projects into the engine flowpath. The variable vane extends across the engine flowpath. The variable vane includes a pivot axis and an airfoil. The variable vane is configured to pivot about the pivot axis between a first position and a second position. The airfoil extends spanwise along a span line between a first end and a second end. The airfoil extends chordwise along a chord line between a leading edge and a trailing edge. A recess extends spanwise into the airfoil from the first end. The airfoil, at the first end, is spaced from the protuberance when the variable vane is in the first position. The airfoil, at the first end, is aligned with the protuberance and the protuberance projects into the recess when the variable vane is in the second position.

Abstract: A gas turbine engine apparatus includes a variable vane. The variable vane includes a pivot axis and an airfoil. The variable vane is configured to pivot about the pivot axis between a first position and a second position. The airfoil extends spanwise along a span line between a first end and a second end. The airfoil extends chordwise along a chord line between a leading edge and a trailing edge. The chord line is angularly offset from a reference plane containing the pivot axis by a twist angle. A first section of the airfoil is disposed at the first end. The twist angle varies as the first section extends spanwise along the span line. A second section of the airfoil is disposed spanwise between the first section and the second end. The twist angle is uniform as the second section extends spanwise along the span line.

Abstract: A diffuser pipe has a tubular body defining a pipe center axis extending therethrough. The tubular body includes a first portion extending in a generally radial direction from an inlet of the tubular body, a second portion extending in a generally axial direction and terminating at a pipe outlet, and a bend portion fluidly linking the first portion and the second portion. The tubular body has a length defined between the inlet and the pipe outlet. The tubular body has cross-sectional profiles defined in a plane normal to the pipe center axis. An area of the cross-sectional profile at the pipe outlet is at least 20% greater than an area of the cross-sectional profile at a point upstream from the pipe outlet a distance corresponding to 10% of the length of the tubular body.

Abstract: An air intake plenum for a gas turbine engine is provided that includes an axial centerline, first and second gas path surfaces, and a plurality of struts. The gas path surfaces are spaced apart from one another and define at least a portion of a plenum interior. The struts extend lengthwise between the gas path surfaces. Each strut has a cross-section geometry. The cross-section geometry has a center, and major and minor axes. The struts are circumferentially spaced apart from one another within the plenum. Each strut is oriented at a clocking angle theta. The clocking angle theta for each respective strut is disposed between the major axis of that strut and a line that intersects the cross-section geometry center of that strut and the axial centerline. At least one strut of the plurality of struts is oriented at a clocking angle theta that is greater than zero.

Abstract: A diffuser pipe has a tubular body defining a pipe center axis extending therethrough. The tubular body includes a first portion extending in a generally radial direction from an inlet of the tubular body, a second portion extending in a generally axial direction and terminating at a pipe outlet, and a bend portion fluidly linking the first portion and the second portion. The tubular body has a length defined between the inlet and the pipe outlet. The tubular body has cross-sectional profiles defined in a plane normal to the pipe center axis. An area of the cross-sectional profile at the pipe outlet is at least 20% greater than an area of the cross-sectional profile at a point upstream from the pipe outlet a distance corresponding to 10% of the length of the tubular body.

Abstract: A compressor for an aircraft engine. A rotor includes blades rotatable about an axis. Blade tips extend between leading and trailing edges. A shroud surrounds the rotor, with an inner surface surrounding the tips. Grooves are defined in the shroud inner surface adjacent the tips. The grooves extend circumferentially about the shroud and radially from inlet openings to closed end surfaces. Groove sidewalls extend circumferentially about the axis. The grooves are axially spaced-apart, the most upstream inlet opening having an upstream end disposed upstream of the leading edges of the blades. The grooves have a swept angle from the inner surface, with a center of the inlet openings is axially offset of a center of the closed-end surfaces. The grooves span an overall axial distance corresponding to 30% or more of the blades’ chord length. The grooves have circumferential interruptions defined by baffles, and extend non-continuously around a shroud circumference.

Abstract: Methods and systems for detecting fraudulent activity at a self-checkout terminals of a retail store include a scanner for scanning an identifier of a candidate product located in the product-scanning area of the self-checkout terminal, and one or more sensors that detect at least one physical characteristic of the candidate product located in the product-scanning area of the self-checkout terminal. A computing device then correlates the obtained electronic data corresponding to actual identifying characteristic information associated with the candidate product to the reference physical characteristic information associated with the reference product in order to generate a similarity score between the actual and reference physical characteristic information.

Abstract: In some embodiments, apparatuses and methods are provided herein useful to detecting a mis-scan of an item. In some embodiments, there is provided a system for detecting a mis-scan of an item for purchase comprising a checkout station; a first staging location; a second staging location; a first area of interest at the checkout station; a second area of interest at the checkout station; a camera; and a control circuit configured to: receive an identifier of a first item; detect a hand of a user purchasing the first item, the first item, and a scanner on a first image captured by the camera; in response to the detection of the hand, the first item, and the scanner, initiate detection of mis-scan items during a checkout process; determine that a payment transaction has been received; and stop the detection of mis-scan items.

Abstract: Many linear alpha olefin (LAO) syntheses form a range of LAO products when oligomerizing ethylene in the presence of a Ziegler-type catalyst. The range of products typically requires a plurality of distillation columns to separate the LAO products up to a desired carbon count, but such approaches may be energy- and capital-intensive. LAO product separation using at least one dividing wall column may lessen these burdens. Methods for separating LAOs may comprise: providing a pre-processed product stream comprising Cg+ linear alpha olefins (LAOs) to a first of a series of distillation columns, at least one member of the series of distillation columns comprising a dividing wall column; and separating an overhead stream comprising a first LAO from the dividing wall column and one or more side streams from the dividing wall column, each side stream comprising a different LAO that also differs from the first LAO.

Abstract: An impeller for a centrifugal compressor, the impeller comprising: a hub defining a rotation axis about which the impeller is rotatable; and a vane extending from the hub, the vane having a leading edge, a trailing edge, and a chord defined therebetween, a pressure side of the vane and a suction side of the vane opposite the pressure side, a vane thickness defined transversely between the pressure side and the suction side, the vane thickness reducing over at least a downstream 40% of the chord, the vane thickness having a trailing edge thickness value at the trailing edge of between 40% and 80% of a maximum thickness value of the vane thickness.

Abstract: A diffuser pipe has a tubular body extending from an inlet to an outlet and increasing in cross-sectional area from the inlet toward the outlet. The outlet has a radially inner wall, a radially outer wall, and side walls joining the radially inner wall to the radially outer wall. The outlet has an elliptigon shape in which both the radially inner wall and the radially outer wall are curved. A radius of curvature of the radially outer wall is different from a radius of curvature of the radially inner wall.

Abstract: A diffuser for a compressor of a gas turbine engine is disclosed. The diffuser has a plurality of diffuser pipes circumferentially distributed about an axis of the compressor, each of the plurality of diffuser pipes extending from an inlet to an outlet and having a bend section between the inlet and the outlet, a low pressure side and an opposite high pressure side. A recirculation conduit defines a recirculation path from a first flow region to a second flow region in one or more of the plurality of the diffuser pipes, the first flow region having a greater static pressure than that of the second region, the recirculation conduit having a conduit inlet and a conduit outlet, at least the conduit outlet located within the low pressure side of one of the plurality of the diffuser pipes.

Abstract: A diffuser for a compressor of a gas turbine engine is disclosed. The diffuser has a plurality of diffuser pipes circumferentially distributed about an axis of the compressor, each of the plurality of diffuser pipes extending from an inlet to an outlet and having a bend section between the inlet and the outlet, a low pressure side and an opposite high pressure side. A recirculation conduit defines a recirculation path from a first flow region to a second flow region in one or more of the plurality of the diffuser pipes, the first flow region having a greater static pressure than that of the second region, the recirculation conduit having a conduit inlet and a conduit outlet, at least the conduit outlet located within the low pressure side of one of the plurality of the diffuser pipes.

Abstract: The gas turbine engine described includes a first centrifugal compressor, a second centrifugal compressor, and intercompressor pipes extending therebetween. The intercompressor pipes fluidly interconnect an exit of a first impeller of the first centrifugal compressor and an inlet of a second impeller of the second centrifugal compressor. The intercompressor pipes have heat transfer structures on outer surfaces thereof to increase convective heat transfer.

Abstract: Many linear alpha olefin (LAO) syntheses form a range of LAO products when oligomerizing ethylene in the presence of a Ziegler-type catalyst. The range of products typically requires a plurality of distillation columns to separate the LAO products up to a desired carbon count, but such approaches may be energy- and capital-intensive. LAO product separation using at least one dividing wall column may lessen these burdens. Methods for separating LAOs may comprise: providing a pre-processed product stream comprising Cg+ linear alpha olefins (LAOS) to a first of a series of distillation columns, at least one member of the series of distillation columns comprising a dividing wall column; and separating an overhead stream comprising a first LAO from the dividing wall column and one or more side streams from the dividing wall column, each side stream comprising a different LAO that also differs from the first LAO.

Abstract: According to some embodiments, a system, method and non-transitory computer-readable medium are provided comprising a Hypothesis Generation Engine (HGE) to receive one or more property target values for a material; a memory for storing program instructions; an HGE processor, coupled to the memory, and in communication with the HGE, and operative to execute program instructions to: receive the one or more property target values for the material; analyze the one or more property target values as compared to one or more known values in a knowledge base; generate, based on the analysis, an initial set of hypothetical structures, wherein each hypothetical structure includes at least one property target value; execute a likelihood model for each candidate material to generate a likelihood probability for each hypothetical structure, wherein the likelihood probability is a measure of the likelihood that the hypothetical structure will have the target property value; convert each hypothetical structure into a natural

Abstract: A gas turbine engine for an aircraft having a centrifugal compressor including an impeller with impeller blades extending from a hub, the impeller mounted for rotation about a central longitudinal axis within an outer shroud. A main flow passage wall is located on a shroud side near the impeller exit, the main flow passage wall separating a cavity disposed on the shroud side from the main flow passage. One or more apertures are defined through the main flow passage wall and extending along a respective aperture axis between the cavity and the main flow passage. The apertures have a main flow passage side opening located radially outward from the impeller exit. The aperture axis is disposed at a radial angle relative to the central longitudinal axis.

Abstract: A compressor diffuser for a gas turbine engine is described which includes diffuser pipes having a tubular body defining a pipe center axis extending therethrough. The tubular body includes a first portion extending in a generally radial direction, a second portion extending in a generally axial direction and terminating at a pipe outlet, and a bend portion fluidly linking the first portion and the second portion. A first curved side wall of the tubular body along the second portion is shorter than a second curved side wall of the tubular body along the second portion. The second portion of the tubular body has a cross-sectional profile defined in a plane normal to the pipe center axis. The first curved side wall of the cross-sectional profile has a smaller radius than a radius of the second curved side wall of the cross-sectional profile.