摘要:
A mold for molding a core for use in casting hollow parts includes, a lower mold portion and an upper mold portion defining therein a cavity corresponding to the outer surface of the core. The lower mold portion includes a cutout disposed along a parting line defined between the lower mold portion and the upper mold portion and opening onto the cavity. After introduction of a ceramic slurry mixture into the mold the upper mold portion is removable, to expose a first side of the core and a protective flash formed in the cutout. Desirably, a heat shield is positioned over the protective flash and the exposed portion of the parting line of the lower mold portion so that the lower mold portion is not exposed directly to a flame during a preliminary firing to impart sufficient strength to the ceramic core so that the ceramic core may be handled. Providing the core with a protective flash allows the mold to be advantageously fabricated by rapid tooling technique such as by a stereolithography process from a plastic material.
摘要:
A mold for molding a core for use in casting hollow parts includes, a lower mold portion and an upper mold portion defining therein a cavity corresponding to the outer surface of the core. The lower mold portion includes a cutout disposed along a parting line defined between the lower mold portion and the upper mold portion and opening onto the cavity. After introduction of a ceramic slurry mixture into the mold the upper mold portion is removable, to expose a first side of the core and a protective flash formed in the cutout. Desirably, a heat shield is positioned over the protective flash and the exposed portion of the parting line of the lower mold portion so that the lower mold portion is not exposed directly to a flame during a preliminary firing to impart sufficient strength to the ceramic core so that the ceramic core may be handled. Providing the core with a protective flash allows the mold to be advantageously fabricated by rapid tooling technique such as by a stereolithography process from a plastic material.
摘要:
A method for operating a gas turbine engine including a high pressure compressor, a variable inlet guide vane assembly and a water injection apparatus for injecting water into a flow of the engine is provided. The method comprises transmitting engine operating parameters including a temperature of the gas flow at an outlet of the high pressure compressor, T3, to an engine controller, using the controller to regulate a flow of water injected into the gas flow and to adjust a relative position of the inlet guide vane assembly until engine full power is about reached as determined by a pre-defined T3 operating parameter limit, and adjusting the controller to then facilitate operation of the engine with an increased output without exceeding the pre-defined T3 operating parameter limit.
摘要:
The present invention involves a process for increasing coolant side surface roughness on castings such as airfoils, shrouds, nozzles or the like by electrical discharge machining (EDM). An EDM electrode is shaped to fill completely or a portion of a cavity in the casting, the electrode is then connected to an electric discharge machine, and the internal surfaces of the internal core cavity are then machined to form a roughened surface.
摘要:
A pair of hollow elongated insert bodies are disposed in one or more of the nozzle vane cavities of a nozzle stage of a gas turbine. Each insert body has an outer wall portion with apertures for impingement-cooling of nozzle wall portions in registration with the outer wall portion. The insert bodies are installed into the cavity separately and spreaders flex the bodies toward and to engage standoffs against wall portions of the nozzle whereby the designed impingement gap between the outer wall portions of the insert bodies and the nozzle wall portions is achieved. The spreaders are secured to the inner wall portions of the insert bodies and the bodies are secured to one another and to the nozzle vane by welding or brazing.