초록 ▼

A system for controlling aeromechanical instability or flutter in turbofan engines having fan blades employs a sensor, such as an off-blade static pressure sensor or proximity detector mounted on a turbofan engine at an inlet of a rotor of the engine for generating a signal to detect resonance of th

A system for controlling aeromechanical instability or flutter in turbofan engines having fan blades employs a sensor, such as an off-blade static pressure sensor or proximity detector mounted on a turbofan engine at an inlet of a rotor of the engine for generating a signal to detect resonance of the turbofan blades at frequencies associated with flutter. A controller is coupled to the sensor for generating by spatial Fourier decomposition from the sensor signal a command signal comprising a real time amplitude component and a spatial phase of disturbances of a predetermined nodal diameter and coincident with a natural frequency of resonance of a predetermined structural mode of the fan blades in the stationary frame. An actuator, such as a bleed valve or acoustic speaker, is mounted on the turbofan engine for damping flutter dynamics in response to the amplitude of the command signal.

대표청구항 ▼

[What is claimed is:] [22.]sensing blade resonance associated with stall flutter at a location outwardly from the turbofan blades at an inlet of a rotor of the engine and generating a sensor signal indicative of the inception of stall flutter;generating from the sensor signal a command signal includ

[What is claimed is:] [22.]sensing blade resonance associated with stall flutter at a location outwardly from the turbofan blades at an inlet of a rotor of the engine and generating a sensor signal indicative of the inception of stall flutter;generating from the sensor signal a command signal including a real time amplitude component and a spatial Fourier component (SFC) of disturbances of a predetermined nodal diameter and coincident with a natural frequency of resonance of a predetermined structural mode of the fan blades; anddamping stall flutter dynamics in response to the command signal.