Method of monitoring blade vibration in a turbine engine

摘要

A rotor blade measurement system includes a microwave source (26) and a probe (28). A directional coupler (34) is attached to the source (26) and the probe (28). A detector (36) is attached to the directional coupler (34). The probe directs a microwave signal (30) toward a rotor (20) such that during rotation the rotor blade (22) will pass through the path of the microwave signal (30). As the rotor blade (22) passes, the microwave signal (30) is reflected back to the probe (28). The directional coupler (34) separates the original microwave signal (30) and the reflected signal (32). The detector (36) then determines the energy level of the reflected signal (32). As each rotor blade (22) passes the microwave signal (30) it generates a reflected signal that can be analyzed over time. From the length and shape of the waveform of the reflected signal (32) the amount of twisting and flutter in a rotor blade can be determined.