Abstract: A turbine blade includes a first side wall including a first tip edge, a second side wall opposite the first side wall and including a second tip edge, a tip wall between the first and second side walls, the tip wall recessed from the first tip edge of the first side wall and the second tip edge of the second side wall forming a coolant cavity, a tip recess cavity, a first parapet wall on the first side wall, and a second parapet wall on the second side wall, the coolant cavity defined by the tip wall, and the tip recess cavity defined by the tip wall, and the first and second parapet walls, a step formed between the first tip edge and the tip wall, a cooling hole through the first parapet wall, the step, and the tip wall, the cooling hole including an open and a closed channel section.

Abstract: This invention relates to methods and devices for entropy-based location fingerprinting, in particular for use over wireless local-area networks (WLANs). The invention has particular application in localization for indoor environments. In embodiments of the invention, an entropy-based fingerprint is determined at a number of predetermined locations within the desired area of localization during an off-line phase and subsequently used in an on-line mode to determine the location of a receiver. In particular embodiments, the fingerprint is a vector of entropy estimates of the channel transfer function (CTF) between a mobile terminal and all access points within coverage. The invention seeks to provide a fingerprinting localization solution that has a simplicity of structure, leading to advantages in storage and pattern recognition requirements, and robustness by proving a unique measure of information that is related to the channel experienced at the location of the mobile terminal.

Abstract: Gas turbine engines and methods for cooling components thereof with mid-impeller bleed (MIB) cooling air having a pressure are provided. The gas turbine engine has a compressor comprising an impeller body and an impeller shroud at least partially surrounding the impeller body. The impeller shroud has a plurality of MIB openings disposed therein. At least one edge treatment is provided thereto. The edge treatment substantially preserves pressure of the cooling air during entrance into and discharge out of the MIB opening. The plurality of MIB openings may be extended MIB openings in a thickened impeller shroud. The centerline of the MIB openings may be oriented to be substantially aligned with an averaged local absolute flow velocity vector of the cooling air at the inlet section of the MIB opening in order to extract cooling air in a direction that has a vector component in a tangential, an axial, and a radial flow direction.

Abstract: A turbine blade assembly includes an airfoil, a platform, and a first cover plate. A center flow path extends through the platform in communication with an internal cooling circuit of the airfoil, which extends from a first side of the platform. A second side of the platform is located opposite the platform from the first side. An edge of the platform extends between the first and second sides and, a first passage is formed between the first and second sides and includes a first inlet and a first outlet. The first passage extends from the center flow path toward the platform edge, and a first groove is formed on the second side of the platform and extends from the first outlet of the first passage toward the edge of the platform. The first cover plate is disposed over the second side of the platform covering the first groove.

Abstract: A turbine blade includes a convex suction side wall, a concave pressure side wall, a tip wall, an internal cooling circuit, and a plurality of tip edge channels. The tip wall is recessed from a first tip edge of the suction side wall and a second tip edge of the concave pressure side wall to define a suction side wall tip section and a pressure side wall tip section, and the suction side wall tip section is shorter than the pressure side wall tip section. The internal cooling circuit is formed at least partially between the convex suction side wall, the concave pressure side wall, and the tip wall. The plurality of tip edge channels formed through the first tip edge of the convex suction side wall extend to the internal cooling circuit. Methods of manufacturing turbine blades are also provided.

Abstract: A turbine blade includes a first side wall including a first tip edge, a second side wall opposite the first side wall and including a second tip edge, a tip wall between the first and second side walls, the tip wall recessed from the first tip edge of the first side wall and the second tip edge of the second side wall forming a coolant cavity, a tip recess cavity, a first parapet wall on the first side wall, and a second parapet wall on the second side wall, the coolant cavity defined by the tip wall, and the tip recess cavity defined by the tip wall, and the first and second parapet walls, a step formed between the first tip edge and the tip wall, a cooling hole through the first parapet wall, the step, and the tip wall, the cooling hole including an open and a closed channel section.

Abstract: An impeller or axial stage compressor disk backface shroud for use with a gas turbine engine is disclosed. The backface shroud includes, but is not limited to, a substantially funnel shaped body having a surface. The substantially funnel shaped body is configured to be statically mounted to the gas turbine engine substantially coaxially with the impeller or axial stage compressor disk. The surface and a backface of the impeller or axial stage compressor disk form a cavity that guides an airflow portion to a turbine when the substantially funnel shaped body is mounted coaxially with the impeller or axial stage compressor disk and axially spaced apart therefrom. The airflow portion has a tangential velocity and a recessed groove in the surface of the backface shroud is oriented generally transversely to the tangential velocity to at least partially interfere with the airflow portion, thus affecting static pressure in the cavity.

Abstract: A turbine blade assembly includes an airfoil, a platform, and a first cover plate. A center flow path extends through the platform in communication with an internal cooling circuit of the airfoil, which extends from a first side of the platform. A second side of the platform is located opposite the platform from the first side. An edge of the platform extends between the first and second sides and, a first passage is formed between the first and second sides and includes a first inlet and a first outlet. The first passage extends from the center flow path toward the platform edge, and a first groove is formed on the second side of the platform and extends from the first outlet of the first passage toward the edge of the platform. The first cover plate is disposed over the second side of the platform covering the first groove.

Abstract: An air-cooled turbine blade is provided having an airfoil shape defined by a convex suction side wall, a concave pressure side wall, a leading edge, a trailing edge, a root and a tip, the walls and the tip each including an interior surface that defines an interior with the root, the trailing edge including a plurality of slots formed thereon. The blade includes a suction side flow circuit formed therein comprising a forward and an aft flow circuit. The blade also includes a tip flow circuit extending along the tip interior surface to at least one of the trailing edge slots and including a first and a second opening, the first opening in flow communication with the suction side forward flow circuit outlet, and the second opening in flow communication with a cross-over hole of the suction side aft flow circuit. Methods of manufacturing the blade are also provided.

Abstract: A turbine blade includes a convex suction side wall, a concave pressure side wall, a tip wall, an internal cooling circuit, and a plurality of tip edge channels. The tip wall is recessed from a first tip edge of the suction side wall and a second tip edge of the concave pressure side wall to define a suction side wall tip section and a pressure side wall tip section, and the suction side wall tip section is shorter than the pressure side wall tip section. The internal cooling circuit is formed at least partially between the convex suction side wall, the concave pressure side wall, and the tip wall. The plurality of tip edge channels formed through the first tip edge of the convex suction side wall extend to the internal cooling circuit. Methods of manufacturing turbine blades are also provided.

Abstract: An air-cooled turbine blade is provided having an airfoil shape defined by a convex suction side wall, a concave pressure side wall, a leading edge, a trailing edge, a root and a tip, the walls and the tip each including an interior surface that defines an interior with the root, the trailing edge including a plurality of slots formed thereon. The blade includes a suction side flow circuit formed therein comprising a forward and an aft flow circuit. The blade also includes a tip flow circuit extending along the tip interior surface to at least one of the trailing edge slots and including a first and a second opening, the first opening in flow communication with the suction side forward flow circuit outlet, and the second opening in flow communication with a cross-over hole of the suction side aft flow circuit. Methods of manufacturing the blade are also provided.

Abstract: A gas turbine engine is configured to use relatively cool, low pressure air discharged from a low pressure compressor to supply buffer air to lubrication sump seals. The engine is further configured such that the lubrication sump is thermally layered by isolating relatively hot, high pressure compressor air from the sump by utilizing a warm vent mixing cavity, which is located radially between of the hot high pressure compressor air and the cool buffer air, which is located in a buffer cavity between the vent cavity and the sump.

Abstract: A gas turbine engine is configured to use relatively cool, low pressure air discharged from a low pressure compressor to supply buffer air to lubrication sump seals. The engine is further configured such that the lubrication sump is thermally layered by isolating relatively hot, high pressure compressor air from the sump by utilizing a warm vent mixing cavity, which is located radially between of the hot high pressure compressor air and the cool buffer air, which is located in a buffer cavity between the vent cavity and the sump.

Abstract: A thin wall cooling system has multiple in-wall channels traversing a thin wall structure such as the wall of a gas turbine engine blade or vane. The blade has a hollow interior that may be divided into multiple cavities. Coolant is introduced into an entry opening of each in-wall channel and then discharged through exit openings into the vane cavities. The coolant then exits the cavities by through wall channels to discharge the coolant to form a cool air film on the external surface of the blade. This combination allows improved cooling control for structures that experience an elevated temperature environment, as for example, the flow of hot gas across the exterior surface of a gas turbine engine blade.

Abstract: A thin wall cooling system has multiple in-wall channels traversing a thin wall structure such as the wall of a gas turbine engine blade or vane. The blade has a hollow interior that may be divided into multiple cavities. Coolant is introduced into an entry opening of each in-wall channel and then discharged through exit openings into the vane cavities. The coolant then exits the cavities by through wall channels to discharge the coolant to form a cool air film on the external surface of the blade. This combination allows improved cooling control for structures that experience an elevated temperature environment, as for example, the flow of hot gas across the exterior surface of a gas turbine engine blade.