Abstract:
A reduction in excitation amplitudes affecting turbine blade durability in a turbine nozzle assembly having a plurality of vanes and turbine blades, includes: identifying a turbine blade design of the turbine nozzle assembly; performing a modal model analysis of at least one of the turbine blades in the turbine blade design; reducing aerodynamic impact by ensuring that each of the turbine blades is free of aero-excitation from an upstream flow at the vanes in an operating speed range; identifying blade natural frequencies with respect to the nozzle vanes; and modifying a trailing edge of at least one of the vanes to reduce the excitation amplitudes.
Abstract:
A rotor blade comprises a blade platform and an airfoil. The airfoil comprises a blade tip, a leading edge, and a trailing edge with a stiffening compound lean contour. The blade tip is radially opposite the blade platform, and defines a blade span between the blade itself and the blade platform. The leading and trailing edges extend from the blade platform to the blade tip to define blade chords between the leading edge and the trailing edge. The compound lean contour comprises a positive lean section located at the lean tip, and extending along a lean axis to a lean end. The negative lean section is located radially inward of the positive lean section, and extends along the lean axis to the lean end.
Abstract:
Método para reducir las amplitudes de excitación que afectan a la durabilidad de los álabes de turbina en un conjunto de boquilla de turbina que tiene una pluralidad de paletas (10) y álabes (32) de turbina, que comprende las etapas de: identificar un diseño de álabe de turbina de dicho conjunto de boquilla (20) de turbina; realizar un análisis de modelo modal de al menos una de dichos álabes (32) de turbina en dicho diseño de álabe de turbina utilizando un ordenador; garantizar que cada uno de dichos álabes (32) de turbina no sufra aero-excitación de un flujo de aguas arriba en dichas paletas (10) en un rango de velocidad de funcionamiento; identificar las frecuencias naturales de los álabes con respecto a dichas paletas (10) utilizando dicho ordenador; caracterizado por que el método comprende, además, las etapas de: determinar al menos una modificación a un borde de salida (42, 44) de al menos una de dichas paletas para reducir las amplitudes de excitación, y modificar al menos una de dichas paletas (10) en dicho borde de salida (42, 44) de acuerdo con la determinación de la etapa anterior; y - realizar un análisis CFD para modificar el campo de presión local mediante la descarga de aire en el borde de salida de la aleta de la boquilla para evitar la acumulación de la energía del fluido extraída por dichos álabes; modificar un campo de presión local mediante la utilización de un flujo de descarga de aire próximo a dicho borde de salida (42, 44) de acuerdo con el análisis CFD de la etapa anterior.
Abstract:
A reduction in excitation amplitudes affecting turbine blade durability in a turbine nozzle assembly having a plurality of vanes and turbine blades, includes: identifying a turbine blade design of the turbine nozzle assembly; performing a modal model analysis of at least one of the turbine blades in the turbine blade design; reducing aerodynamic impact by ensuring that each of the turbine blades is free of aero-excitation from an upstream flow at the vanes in an operating speed range; identifying blade natural frequencies with respect to the nozzle vanes; and modifying a trailing edge of at least one of the vanes to reduce the excitation amplitudes.
Abstract:
A reduction in excitation amplitudes affecting turbine blade durability in a turbine nozzle assembly having a plurality of vanes and turbine blades, includes: identifying a turbine blade design of the turbine nozzle assembly; performing a modal model analysis of at least one of the turbine blades in the turbine blade design; reducing aerodynamic impact by ensuring that each of the turbine blades is free of aero-excitation from an upstream flow at the vanes in an operating speed range; identifying blade natural frequencies with respect to the nozzle vanes; and modifying a trailing edge of at least one of the vanes to reduce the excitation amplitudes.