Lisa

Multi-stage Axial Turbine Research Facility (LISA)

LISA is a state-of-the-art axial research turbine facility engineered and assembled at LEC. Numerous projects have been completed, and more are still ongoing, in the facility; these projects primarily focus on efficiency improvements. Both steam and gas turbine cases, either shrouded or unshrouded, are investigated. The interchangeability of rings and blade rows allows for unique research on the topics of endwall contouring and tip clearance management. The possibility to inject air through a special compressor unit facilitates studies in the area of tip leakage management through tip injection as well as the optimization of blade cooling techniques.

LISA is a quasi–closed type turbine and includes a radial compressor, a two-stage water-to-air heat exchanger and a calibrated venturi nozzle for mass flow measurements. Downstream of the turbine, the air-loop is open to atmospheric conditions. The radial, one stage compressor has a maximum power of 735 kW and can deliver a pressure ratio of 1.5. The turbine inlet temperature (TET) is controlled by the heat exchanger to an accuracy of 0.3%. The venturi nozzle was calibrated together with the entire loop duct system, in order to assess the effects of the bend and struts in the pipes. The RPM is kept constant within ±0.5min-1 / 3000RPM by a DC generator. 

The generated turbine power is fed back into the electrical grid through a DC generator. LISA can accommodate turbines with up to two stages, having two individual shafts for each stage. Two different torquemeters can independently measure each stage’s power. The rig is designed to accommodate a broad range of measurement techniques, with emphasis on unsteady flow measurement techniques. LISA offers both multiple probe access at the exit of blade rows for unsteady data acquisition, as well as capability for inter-stator measurements.  Both FRAP and FENT are applied in LISA. Moreover optical access enables measurements techniques such as PIV to be used. A mass flow by-pass safety system at the compressor exit and two safety couplings at the turbine rotor shaft and the gearbox ensure an automatic shut down during emergency.