The present work aims at characterizing experimentally the mechanisms resulting of an air injection from a slot located on a NACA0015 hydrofoil able to inject high airflow rates into high-speed waterflows (from 10 to 25 m/s). It represents a further step towards understanding the phenomena that occur in aerating turbines currently studied within the NSERC-GE Chair at Polytechnique Montréal.
This work first exposes the design of the hydrofoil itself. It also describes the simulations to optimize the inner air chamber, aiming to produce a most homogeneous air velocity profile. Finally, validations and some early results are discussed. Multiple conditions are generated with various airflow rates and angles of attack. Individual size, velocity and distribution of bubbles leading to local void fraction are measured with a fiber optic probe. Pressure gages located around the foil and strain gages mounted on the foil provide useful additional information on the effects of air injection on the loads and flow characteristics.