Research Service Offer

GMBU Halle e.V. has been working on the development of vibroacoustic methods for analysing triboprocesses and cavitation in the running machines for almost 20 years. The concepts should support fault diagnostics and fault condition prognosis.

The approach correlates (faulty) dynamic machine states and a broad range of vibration measurements in order to be able to identify the development of malfunctions through to wear.
The main areas of application are the lubricated sliding-rolling tribocontacts in gear wheels and the discrimination of cavitation phenomena in fluid machines. The research service offer includes (a.o.):

• FEM simulations of transducers, vibration and sound wave propagation in conjunction with machine geometry and dynamics,
• Adaptation of the AE-measurement for the investigation of malfunctions and wear in gearboxes, fluid machines and fluid apparatus etc.,
• The development and adaptation of vibroacoustic measurement chains consisting of sensor, signal amplifier, measuring board through to an (automated) signal evaluation,
• Selection, validation and comparison (benchmark tests) of a broad range of sensors (accelerometers, AE sensors, micro-/Hydrophones) for condition monitoring,
• Validation of measuring methods, measuring chains and sensors on GMBU’s own cavitation and transmission test benches and plants,
• Accompanying and carrying out measurement campaigns at the customer’s request on their test benches or at users’ premises.

TESTPLANTS UND EQUIPMENT

To test the vibroacoustic measurement and monitoring concepts, a series of (laboratory) technical test stands were set up in which cavitation and tribocontacts can be carried out under the most defined conditions possible (see individual descriptions):

• Gearbox test rig (DOWNLOAD GEAR Wheel Meshing),
• Test rig for laser-induced generation of cavitating individual bubbles and investigation of collapse, and jet dynamics with a high-speed camera,
• Test rigs for investigaton of cavitation in nozzles and orifices,
• Cavitation test rig for pumps (under construction),
• Test rig for determining cavitation erosion on ASTM 32-16.

The test stands are equipped with an extensive range of high-quality measuring devices (selection):

• Non-contact measurements with a single-point laser vibrometer (Polytec),
• Visualisation of cavitating fluids and flows with a high-speed camera,
• Vibroacoustic sensors and transducers from the Hz to the MHz range (accelerometer piezotransducer, hydrophone, microphone up to 80 kHz),
• Hardware solutions with fast measuring cards (high digital bandwidth),
• Software for freely programmable data evaluation and data visualisation.

The test rigs and sensor equipment are compatible with the requirements of harsh industrial environments. The measurement technology can therefore also be used on customers test benches and real world applications.