Method for Designing a Low-Pressure Turbine of an Aircraft Engine, and Low-Pressure Turbine

摘要

A low-pressure turbine of a gas turbine is disclosed. The turbine comprises a number of stages arranged one behind the other in an axial manner in the flow-through direction of the turbine. Each stage is formed from a fixed vane ring having a number of vanes and from a rotating blade ring having a number of blades. Each stage is characterized by a characteristic value vane-to-blade ratio that indicates the ratio of the number of vanes to the number of blades within a stage. One of the stages of the turbine is designed in such a manner that, in the event of noise-critical conditions of the turbine, the characteristic value vane-to-blade ratio of this stage is between a lower cut-off limit for mode k=-1 of the blade-passing frequency (BPF) of said stage and an upper cut-off limit for the mode k=-2 of the blade-passing frequency (BPF) of this stage.