The GELARA-Project

The test rigs of the Chair of Thermal Turbomachines and Aeroengines at the Ruhr University Bochum was commissioned in 1984 and hosts a portfolio of compressor as well as turbine test beds. Among the latter, the large two-sided, axial-radial turbine rigs allows experimental investigations of model high-pressure turbines in technologically relevant configurations. Currently, only the 4-stage axial machine is actively used, generating about 1 MW shaft power output, whilst the high-speed expander (max. rotation speed 24.500 rpm) will be commissioned during a further project planned late in 2024. The turbine is equipped with a hydraulic break system connected to the central cooling water circuit of the university where the generated power is thermally dissipated. The break is capable of imposing a variable load thus enabling an easy control of the turbine’s rotation speed and a stabilisation of the machine during measurements. The now 35-year old hydraulic break will be replaced by a new break system using an electric generator connected to the turbine by means of a high-performance gear box. This will allow immediate usage of the electric energy generated during experimental campaigns, which will be supplied to the asynchronous electrical motor driving the geared compressor, the latter providing the necessary air flow for the turbine by means of a frequency inverter and low-voltage transformer. This arrangement will guarantee stable operability of both sides of the test rig especially in virtue of a fast, real-time control system necessary for high-speed machine whilst allowing substantial energy savings (up to 70-80%) during tests.

• A commissioning of the testrig is foreseen in early summer 2024
• Funding: DFG State Major Instrumentation Programme