Rotor health monitoring and damage detection utilizing a disk spin simulation system

摘要

This paper describes a unique, disk spin simulation system currently being utilized at NASA Glenn Research Center. The system allows for precision controlled spin tests that can facilitate the application of various sensing technologies for in-situ detection of rotor damage. In addition, the disk spin simulation system has the capability for elevated temperatures up to 540 deg C (1000 deg F). The current rotor used to simulate a bladed disk consists of a 46 cm (18 in.) diameter, titanium disk with 30 machined gear teeth. The gear design imitates the blades of a compressor or turbine disk. Operating speeds for the system can reach 10000 revolutions per minute. This allows the system to achieve circumferential velocities paralleling those seen in actual aircraft engines. For this study, a new, innovative capacitive sensing system was used to monitor blade tip clearance (i.e., gear tooth clearance). In turn, the sensor information was employed to calculate the change in the center of mass of the rotor system. The capacitive sensor and corresponding software were analyzed by attaching a localized weight at numerous positions on the disk. Upon calculating the change in the center of mass, the sensitivities of the sensor and software were established. In the end, it is hoped that by studying the motion and position of blades as well as the change in the center of mass of a rotor system, it may be feasible to identify alterations due to damage (e.g., cracks) either in the blades or the disk itself.