Abstract: A process of designing a transonic airfoil that results in an exit deviation angle that is optimized to minimize downstream shock induced flowfield disturbances. Specifically, a design process of a transonic airfoil minimizes pitchwise variation in downstream static pressure that includes determining an airfoil exit deviation angle and downstream turning for reduced shock from a trailing edge of the transonic airfoil.

Abstract: A method and apparatus to reduce the average and maximum temperatures to which the nozzles in the hot-section of gas-turbine engine are subjected is described. The method relates to the circumferential alignment of fuel nozzles and downstream turbine nozzles in a gas turbine engine. This situates the hot-streak emerging from each fuel nozzle in between the like-numbered turbine nozzle airfoils. The most severe operating condition for reducing the durability of nozzle airfoils is the one generating hot operating temperature conditions. By identifying the temperature profile passing through downstream nozzle airfoils, airfoils in static stages can be selectively spaced around the circumference of the ring attached to the casing of the gas turbine engine to avoid high temperature exposure to the airfoils. This method and apparatus mitigates the worst oxidation and thermo-mechanical fatigue damage in the airfoils by allowing the hot gas regions to pass through the path in between two adjacent airfoils.

Abstract: A method and apparatus to reduce the average and maximum temperatures to which the nozzles in the hot-section of gas-turbine engine are subjected is described. The method relates to the circumferential alignment of fuel nozzles and downstream turbine nozzles in a gas turbine engine. This situates the hot-streak emerging from each fuel nozzle in between the like-numbered turbine nozzle airfoils. The most severe operating condition for reducing the durability of nozzle airfoils is the one generating hot operating temperature conditions. By identifying the temperature profile passing through downstream nozzle airfoils, airfoils in static stages can be selectively spaced around the circumference of the ring attached to the casing of the gas turbine engine to avoid high temperature exposure to the airfoils. This method and apparatus mitigates the worst oxidation and thermo-mechanical fatigue damage in the airfoils by allowing the hot gas regions to pass through the path in between two adjacent airfoils.

Abstract: A method of operating a combined gas and steam turbine cycle system including a steam turbine provided with steam from at least one heat recovery steam generator having a high pressure section and a low pressure section, wherein the steam turbine includes high pressure seals and low pressure seals, includes the steps of:a) when the steam turbine is operating at a load below a self-sealing load, supplying steam at a controlled, predetermined pressure to the high and low pressure seals from the high pressure section of the heat recovery steam generator; andb) after steam from the lower pressure section of the heat recovery stem generator exceeds the predetermined pressure, supplying the high and low pressure seals with steam from the lower pressure section of the heat recovery steam generator at a pressure higher than the predetermined pressure, andc) supplying steam from the high pressure section of the heat recovery steam generator whenever a turbine metal inlet temperature exceeds a predetermined reference t