Structure and Functionality
The ROT II rests on three pillars supported by air bearings. An electric motor rotates the shaft with the test carrier mounted on it. To eliminate aerodynamic damping, operation takes place in a vacuum chamber.
Several options are available on the ROT II for exciting blade vibrations. In addition to permanent magnets, electromagnets can also be used, which offer advantages in controlling the excitation forces.
Several measurement methods are available for measuring the vibrations of the turbine blades. A glass cover on the vacuum chamber enables optical measurement using a laser vibrometer in the rotating system. In addition, strain gauges are used to simultaneously record the strain of the vibrating blades.
To process the strain gauge sensor data, measurement boards are developed for the test carriers, which filter and amplify the sensor data analogously. The data transfer from the rotating to the inertial system is then carried out via a slip ring transmitter. A 60-channel measurement system is available for data acquisition and evaluation. This data is evaluated in real time on the computer and displayed graphically.
