EXPERIMENTAL INVESTIGATIONS OF THE INFLUENCE OF WATER DROPLETS IN COMPRESSOR CASCADES

摘要

This paper presents first results of experiments in a two-phase-flow cascade wind-tunnel. A Phase-Doppler-Anemometry system is used to measure velocity and water droplet-sizes in a compressor cascade. The local velocity with water injected is slower than the air flow without water injection due to droplet inertia and loss of momentum. Ligament formation and breakup caused by Rayieigh-Taylor instabilities is observed at the trailing edge resulting in particle sizes between 20 μm and 30 μm independent of flow velocity and the size of the nozzle used for water injection. Another region in the last third of the suction side is found, where a separation of droplets below 10 μm occurs. A change inflow angle at the cascade outlet is observed depending on water-load and droplet-size in the inlet.