Abstract: A turbine blade in a gas turbine engine includes an airfoil extending in a radial direction. The airfoil has an outer wall delimiting an airfoil interior. The outer wall includes a pressure sidewall and a suction sidewall joined at a leading edge and a trailing edge in a longitudinal direction. A turbulator is disposed in the airfoil interior. The turbulator includes a first row having at least two turbulator ribs spaced apart in the longitudinal direction. The turbulator includes a second row extending in the radial direction from the first row and having at least two turbulator ribs spaced apart in the longitudinal direction.

Abstract: A ring segment assembly includes a ring segment including an impingement pocket having an impingement surface, a plurality of pins extending from the impingement surface, and an impingement plate spaced a non-zero distance from the impingement surface. The plurality of pins are arranged to define a plurality of pinless impingement areas. The impingement plate has a plurality of bumps and a plurality of valleys. The impingement plate defines a plurality of impingement holes. Each impingement hole of the plurality of impingement holes is formed in one of the valleys of the plurality of valleys and positioned opposite one of the plurality of pinless impingement areas.

Abstract: A molding tool (10) for manufacturing cooling features in a ceramic core for a casting process includes a first mold portion (12) comprising a crossover hole forming feature (18); a second mold portion (24) comprising an impingement jet receiving forming feature (30) for forming an impingement jet receiving feature having a desired aiming point (32); and a sacrificial alignment member (34) for extending at least partially into the crossover hole forming feature (18) at least partially into the aiming point (32) of the impingement jet receiving forming feature (30) for substantially aligning a central axis (38) of the crossover hole forming feature (18) with the aiming point (32) to maintain a crossover hole and aiming point alignment during casting to ensure that the jet is directed at the aiming point (32) in a resultant cast part.

Abstract: A turbine blade in a gas turbine engine includes an airfoil extending in a radial direction. The airfoil has an outer wall delimiting an airfoil interior. The outer wall includes a pressure sidewall and a suction sidewall joined at a leading edge and a trailing edge in a longitudinal direction. A turbulator is disposed in the airfoil interior. The turbulator includes a first row having at least two turbulator ribs spaced apart in the longitudinal direction. The turbulator includes a second row extending in the radial direction from the first row and having at least two turbulator ribs spaced apart in the longitudinal direction.

Abstract: A turbine blade tip includes a tip cap disposed over a blade airfoil and having a pressure side edge and a suction side edge. A notch is formed by a radially inward step adjacent to the suction side edge of the tip cap. The notch is defined by a radially extending step wall and a radially outward facing land. The step wall extends radially inward from the suction side edge of the tip cap to the land, whereby the land is positioned radially inward in relation to a radially outer surface of the tip cap. The notch extends along at least a portion of the suction sidewall in a direction from the leading edge to the trailing edge. In a further aspect, a method is provided for servicing a blade that includes machining a suction side notch as described above.

Abstract: A molding tool (10) for manufacturing cooling features in a ceramic core for a casting process includes a first mold portion (12) comprising a crossover hole forming feature (18); a second mold portion (24) comprising an impingement jet receiving forming feature (30) for forming an impingement jet receiving feature having a desired aiming point (32); and a sacrificial alignment member (34) for extending at least partially into the crossover hole forming feature (18) at least partially into the aiming point (32) of the impingement jet receiving forming feature (30) for substantially aligning a central axis (38) of the crossover hole forming feature (18) with the aiming point (32) to maintain a crossover hole and aiming point alignment during casting to ensure that the jet is directed at the aiming point (32) in a resultant cast part.

Abstract: An investment casting core (10) incorporates an alignment guide (24) extending through a body (12) of the core. The alignment guide (24) defines a coolant flow path (92) in a later-cast metal component (76) extending from a coolant outlet opening (90) in an impingement structure (88) to an impingement target area (86) of a cooling feature (84) formed on an impingement cooled surface (82) of the component (76). Methods of making the core (10) and using the core (10) in lost wax investment casting processes are also described.

Abstract: An airfoil for a turbine engine includes an array of pins positioned in an internal cavity of the airfoil, such that cooling channels are defined in the interspaces between adjacent pins. Each pin extends lengthwise from a first airfoil wall to a second airfoil wall and is connected thereto at a first intersection and at a second intersection respectively. The pin has a first cross-sectional shape at a respective intersection and a second cross-sectional shape at an intermediate plane located between the first and second intersections. The first cross-sectional shape includes a closed shape defined by relatively sharp corners and the second cross-sectional shape includes a closed shape defined by relatively rounded corners. A cross-sectional area of the pin at the intermediate plane is greater than a cross-sectional area of the pin at the respective intersection.

Abstract: An airfoil for a turbine engine includes an array of pins positioned in an internal cavity of the airfoil, such that cooling channels are defined in the interspaces between adjacent pins. Each pin extends lengthwise from a first airfoil wall to a second airfoil wall and is connected thereto at a first intersection and at a second intersection respectively. The pin has a first cross-sectional shape at a respective intersection and a second cross-sectional shape at an intermediate plane located between the first and second intersections. The first cross-sectional shape includes a closed shape defined by relatively sharp corners and the second cross-sectional shape includes a closed shape defined by relatively rounded corners. A cross-sectional area of the pin at the intermediate plane is greater than a cross-sectional area of the pin at the respective intersection.

Abstract: An impingement cooling system for a gas turbine engine includes an initial impingement surface (10) with a centrally located opening (12). A plurality of channels (14) and plurality of sub-channels (22) extends radially outward from the opening (12) and are formed by a plurality of fixtures (16) and plurality of sub-fixtures (24) that each separates each adjacent channel (14) and sub-channel (22) respectively. The plurality of fixtures (16) and plurality of sub-fixtures (24) each have a rounded upstream end (18) in a plane parallel relative to the initial impingement surface (10). The plurality of fixtures (16) and the plurality of sub-fixtures (24) each have a concave shape along a middle portion (54, 56) of the fixture (16) and sub-fixture (24) along an axis perpendicular to the initial impingement surface (10).

Abstract: A turbine blade tip includes a tip cap disposed over a blade airfoil and having a pressure side edge and a suction side edge. A notch is formed by a radially inward step adjacent to the suction side edge of the tip cap. The notch is defined by a radially extending step wall and a radially outward facing land. The step wall extends radially inward from the suction side edge of the tip cap to the land, whereby the land is positioned radially inward in relation to a radially outer surface of the tip cap. The notch extends along at least a portion of the suction sidewall in a direction from the leading edge to the trailing edge. In a further aspect, a method is provided for servicing a blade that includes machining a suction side notch as described above.

Abstract: A turbine element for high pressure drop and heat transfer. The turbine element includes a plurality of elements (16) radially placed in columns together aligned in a series of rows of at least four rows across an interior surface of an outer wall of an airfoil (10), creating a pin fin pattern (14) based on the shape of each of the plurality of elements (16), wherein each element (16) includes an inner length between an inner top edge and an inner bottom edge, an inner width between an inner left edge and an inner right edge. The pin fin pattern (14) is highly packed and fills a portion of the interior surface of the outer wall of the airfoil (10).

Abstract: An impingement cooling system for a gas turbine engine includes an initial impingement surface (10) with a centrally located opening (12). A plurality of channels (14) and plurality of sub-channels (22) extends radially outward from the opening (12) and are formed by a plurality of fixtures (16) and plurality of sub-fixtures (24) that each separates each adjacent channel (14) and sub-channel (22) respectively. The plurality of fixtures (16) and plurality of sub-fixtures (24) each have a rounded upstream end (18) in a plane parallel relative to the initial impingement surface (10). The plurality of fixtures (16) and the plurality of sub-fixtures (24) each have a concave shape along a middle portion (54, 56) of the fixture (16) and sub-fixture (24) along an axis perpendicular to the initial impingement surface (10).

Abstract: An arrangement to minimize vibrations in a gas turbine exhaust diffuser is provided. The arrangement includes a projection coupled to an inner cylindrical surface or the outer cylindrical surface of a fluid flow path of the gas turbine exhaust diffuser. The projection minimizes pressure oscillations in the gas turbine exhaust diffuser such that an unsteadiness of the fluid flow surrounding the second tangential strut is reduced. A method to minimize pressure oscillations in a gas turbine diffuser is also provided.

Abstract: A midframe portion (113) of a gas turbine engine (110) is provided, including a compressor section (112) with a last stage blade (124). The compressor section (112) is configured to introduce a radial velocity component into an air flow (111) such that the air flow is discharged from the compressor section (112) at a mixed direction based on a combined longitudinal velocity component and radial velocity component. The midframe portion (113) further includes a manifold (121) to directly couple the air flow from an outlet of the compressor section (112) to an inlet of a respective combustor head (118) of the gas turbine engine (110).

Abstract: A combustor assembly (17) including guide vanes (44) located between an inner cylinder (24) and a flow sleeve (25). Each guide vane (44) includes a circumferentially angled flow directing portion (60) adjacent to a leading edge (46). The leading edge (46) of at least one guide vane (44) can be located radially inward along the longitudinal axis (54) relative to the leading edge (46) of at least one other of the guide vanes (44). The length of the guide vanes (44) may vary, and the circumferential spacing between a first pair of the guide vanes (44) can be different from a spacing between a second pair of the guide vanes (44).

Abstract: An arrangement to control vibrations in a gas turbine exhaust diffuser is provided. The arrangement includes a protrusion coupled to a turbine exhaust cylinder strut for controlling shock induced oscillations in a gas turbine diffuser. The controlled shock induced oscillations minimize pressure fluctuations in the gas turbine exhaust diffuser such that an unsteadiness of the fluid flow surrounding the turbine exhaust cylinder strut is reduced. A method to fluid flow induced vibrations in a gas turbine diffuser is also provided.

Abstract: A combustor assembly (17) including guide vanes (44) located between an inner cylinder (24) and a flow sleeve (25). Each guide vane (44) includes a circumferentially angled flow directing portion (60) adjacent to a leading edge (46). The leading edge (46) of at least one guide vane (44) can be located radially inward along the longitudinal axis (54) relative to the leading edge (46) of at least one other of the guide vanes (44). The length of the guide vanes (44) may vary, and the circumferential spacing between a first pair of the guide vanes (44) can be different from a spacing between a second pair of the guide vanes (44).

Abstract: A power generation system (10). Stationary and rotatable blades (34, 37) are positioned about a rotor (8) to receive exhaust gas (46) from a combustor (6) and to impart an axial velocity component. A section of ductwork (48) is positioned to receive the exhaust gas and has a central transition portion (80t) into which the rotor extends. A spiral portion (80s) of the ductwork comprises a helically shaped flow section (80) extending outwardly from the central portion to provide a helical section of the flow path to carry the exhaust gas away from the central portion. A portion of the flow path along the helically shaped flow section may have an area in cross section which increases as a function of position along the flow path. The spiral portion is positioned to redirect the exhaust in a direction orthogonal to the rotor.

Abstract: A turbine airfoil usable in a turbine engine and having at least one cooling system with an efficient trip strip is disclosed At least a portion of the cooling system may include one or more cooling channels having one or more trip strips protruding from an inner surface forming the cooling channel. The trip strip may have improved operating characteristics including enhanced heat transfer capabilities and a substantial reduction in pressure drop typically associated with conventional trip strips In at least one embodiment, the trip strip may have a cross-sectional area with a first section of an upstream surface of the trip strip being positioned nonparallel and nonorthogonal to a surface forming the cooling system channel extending upstream from the at least one trip strip and a concave shaped downstream surface of the at least one trip strip that enables separated flow to reattach to the cooling fluid flow.