Abstract: A multi-pieces gas turbine engine combustor heat shield is fabricated from sheet metal. The fabrication involves: sheet metal forming a base sheet having opposed hot and cold facing sides, providing cold side details separately from the base sheet, and mounting the cold side details to the cold facing side of the base sheet. The cold side details may be brazed to the base sheet.

Abstract: A modular fuel nozzle tip for a gas turbine engine includes a body defining one or more fuel conveying passages extending therethrough, an annular cap having a radially inner shoulder surface interfacing with the peripheral end surface of the body to define a plurality of air channels extending through the head portion of the modular fuel nozzle tip. At least two fasteners fasten the annular cap to the body.

Abstract: A combustor with a liner where each of the walls has a respective circumferential row of dilution holes defined therethrough adjacent a junction between the primary zone and the dilution zone. In the primary zone, the inner surface of each of the walls is covered by at least one heat shield attached thereto and spaced apart therefrom to allow air circulation between the inner surface and the at least one heat shield, the walls each having a plurality of cooling holes defined therethrough having a smaller diameter than that of the dilution holes. In the dilution zone, the inner surface of each of the walls is free of heat shields, and the walls each have a plurality of effusion cooling holes defined therethrough and having a smaller diameter than that of the dilution holes.

Abstract: Imagers may include analog-to-digital converter circuitry that produces a digital output code from an analog input voltage. The analog-to-digital converter circuitry may include a series of capacitors including a first set of binary-mapped capacitors. The analog-to-digital converter circuitry may include a second set of one or more capacitors that have capacitances that are less than binary-mapped capacitance values. The digital output code may include bits having respective bit positions within the digital output code. During successive-approximation operations performed by the analog-to-digital converter circuitry, each bit of the digital output code may be produced using a corresponding capacitor. Digital processing circuitry such as an image processor may produce a digital value from the digital output code by multiplying the bits of the digital output code with respective weights determined based on the capacitance of the corresponding capacitors.

Abstract: A combustor with a liner where each of the walls has a respective circumferential row of dilution holes defined therethrough adjacent a junction between the primary zone and the dilution zone. In the primary zone, the inner surface of each of the walls is covered by at least one heat shield attached thereto and spaced apart therefrom to allow air circulation between the inner surface and the at least one heat shield, the walls each having a plurality of cooling holes defined therethrough having a smaller diameter than that of the dilution holes. In the dilution zone, the inner surface of each of the walls is free of heat shields, and the walls each have a plurality of effusion cooling holes defined therethrough and having a smaller diameter than that of the dilution holes.

Abstract: A combustor with a liner where each of the walls has a respective circumferential row of dilution holes defined therethrough adjacent a junction between the primary zone and the dilution zone. In the primary zone, the inner surface of each of the walls is covered by at least one heat shield attached thereto and spaced apart therefrom to allow air circulation between the inner surface and the at least one heat shield, the walls each having a plurality of cooling holes defined therethrough having a smaller diameter than that of the dilution holes. In the dilution zone, the inner surface of each of the walls is free of heat shields, and the walls each have a plurality of effusion cooling holes defined therethrough and having a smaller diameter than that of the dilution holes.

Abstract: A fuel stabilization unit includes a fuel inlet and outlet, an oxygen permeable membrane and a vacuum source. The vacuum source employs an ejector and a high pressure fluid to generate an oxygen partial pressure differential across the membrane. A fuel deoxygenation system includes a fuel stabilization unit and a vacuum source. The fuel stabilization unit has a fuel flow path, a vacuum chamber and an oxygen permeable membrane separating the fuel flow path and the vacuum chamber. The vacuum source employs an ejector and a high pressure fluid to reduce pressure in the vacuum chamber to generate an oxygen partial pressure differential across the oxygen permeable membrane. A method for deoxygenating a fuel includes delivering a high pressure fluid to an ejector, generating an oxygen partial pressure differential across an oxygen permeable membrane using only the ejector and removing oxygen from the fuel using the oxygen partial pressure differential.

Abstract: Imagers may include analog-to-digital converter circuitry that produces a digital output code from an analog input voltage. The analog-to-digital converter circuitry may include a series of capacitors including a first set of binary-mapped capacitors. The analog-to-digital converter circuitry may include a second set of one or more capacitors that have capacitances that are less than binary-mapped capacitance values. The digital output code may include bits having respective bit positions within the digital output code. During successive-approximation operations performed by the analog-to-digital converter circuitry, each bit of the digital output code may be produced using a corresponding capacitor. Digital processing circuitry such as an image processor may produce a digital value from the digital output code by multiplying the bits of the digital output code with respective weights determined based on the capacitance of the corresponding capacitors.

Abstract: A gas turbine engine combustor which is cooled by a hybrid cooling apparatus and method. Heat shields cooled by impingement cooling air are present at an upstream section of the combustor liners and exhausted impingement cooling air is substantially discharged outside of the primary zone of the combustor chamber. The single-skinned downstream section of the combustor liners is cooled by effusion cooling.

Abstract: A multi-pieces gas turbine engine combustor heat shield is fabricated from sheet metal. The fabrication involves: sheet metal forming a base sheet having opposed hot and cold facing sides, providing cold side details separately from the base sheet, and mounting the cold side details to the cold facing side of the base sheet. The cold side details may be brazed to the base sheet.

Abstract: A combustor with a liner where each of the walls has a respective circumferential row of dilution holes defined therethrough adjacent a junction between the primary zone and the dilution zone. In the primary zone, the inner surface of each of the walls is covered by at least one heat shield attached thereto and spaced apart therefrom to allow air circulation between the inner surface and the at least one heat shield, the walls each having a plurality of cooling holes defined therethrough having a smaller diameter than that of the dilution holes. In the dilution zone, the inner surface of each of the walls is free of heat shields, and the walls each have a plurality of effusion cooling holes defined therethrough and having a smaller diameter than that of the dilution holes.

Abstract: A fuel stabilization unit includes a fuel inlet and outlet, an oxygen permeable membrane and a vacuum source. The vacuum source employs an ejector and a high pressure fluid to generate an oxygen partial pressure differential across the membrane. A fuel deoxygenation system includes a fuel stabilization unit and a vacuum source. The fuel stabilization unit has a fuel flow path, a vacuum chamber and an oxygen permeable membrane separating the fuel flow path and the vacuum chamber. The vacuum source employs an ejector and a high pressure fluid to reduce pressure in the vacuum chamber to generate an oxygen partial pressure differential across the oxygen permeable membrane. A method for deoxygenating a fuel includes delivering a high pressure fluid to an ejector, generating an oxygen partial pressure differential across an oxygen permeable membrane using only the ejector and removing oxygen from the fuel using the oxygen partial pressure differential.

Abstract: A method of repairing a modular gas turbine fuel nozzle tip, having a fuel-conveying body and an annular cap fastened to the body by at least two fasteners, includes removing the fasteners, replacing the annular cap with a replacement annular cap, and interconnecting the replacement annular cap and the body using new fasteners.

Abstract: A combustor heat shield comprises a heat shield member defining at least one opening for receiving a fuel nozzle. A louver is received in the opening. The louver has a flow diverting portion extending radially outwardly from the opening for directing air along the hot side of the heat shield member.

Abstract: Apparatus and methods detect missing clock edges. An improved phase frequency detector (PFD) can be used in, for example, a phase locked loop (PLL) or a delay locked loop (DLL). Conventional PFDs can miss clock edges. Disclosed is a missing clock edge detection circuit that reliably detects these missing clock edges to correctly activate switches of a charge pump of the PLL or DLL. Embodiments exhibit relatively little of the characteristic polarity reversal of conventional PLL or DLL circuits, which then enables embodiments to operate faster and acquire phase lock quicker than conventional circuits. Such techniques are useful in clock synthesis, clock recovery, and the like. The invention can further include an optional circuit that detects when the missing clock edge detection circuit may have inaccurately determined (false positive) that a clock edge had been missed, to override the corrective action by the missing clock edge detection circuit.

Abstract: A method of repairing a modular gas turbine fuel nozzle tip, having a fuel-conveying body and an annular cap fastened to the body by at least two fasteners, includes removing the fasteners, replacing the annular cap with a replacement annular cap, and interconnecting the replacement annular cap and the body using new fasteners.

Abstract: A combustor heat shield comprises a heat shield member defining at least one opening for receiving a fuel nozzle. A louver is received in the opening. The louver has a flow diverting portion extending radially outwardly from the opening for directing air along the hot side of the heat shield member.

Abstract: A gas turbine combustor is provided with a dome heat shield having a fuel nozzle opening, the opening receiving a floating collar assembly for permitting relative movement between nozzle and heat shield. The floating collar is provided with a louver to provide film cooling to the face of the combustor heat shield and, thus, improve cooling thereof.

Abstract: A combustor heat shield comprises a heat shield member defining at least one opening for receiving a fuel nozzle. A louver is received in the opening. The louver has a flow diverting portion extending radially outwardly from the opening for directing air along the hot side of the heat shield member.

Abstract: A gas turbine engine combustor liner having a plurality of holes defined therein for directing air into the combustion chamber. The plurality of holes provide a greater cooling air flow in regions intermediate each diffuser pipe than in other areas of the combustor liner.