Time-Mean Static Pressure Field In The Stationary Frame Upstream Of The Vane

Time-Mean Flow Angle Distribution In The Stationary Frame Upstream Of The Vane At H/H2=38%

The analysis of the flow field unsteadiness affecting pressure fluctuations in hydraulic turbomachinery is currently in progress at the LFM .

The experimental setup is unconnected from the laboratory hydraulic loop as high water purity is requested to get reliable particle image velocimetry (PIV) measurements. The experimental loop is equipped with a magnetic flow-meter (±0.5% of the sampled value uncertainty) an inductive torque-meter (50 Nm f.r., 0.5% of f.r. uncertainty) and several differential and gauge pressure transducers.

The 2DPIV system is composed of a pulsed Nd:YAG laser (532 nm, 200 mJ), a CCD camera (1280x1024 pixels, maximum double frame rate: 4.5 Hz) and a PIV controller. The phase locked image acquisition is obtained by a magnetic pick-up, on the impeller shaft, connected with a synchronization unit.