Experimental and Numerical Investigations of Inlet Boundary Conditions for a Propeller Turbine Draft Tube

The flow at the draft tube inlet of a propeller turbine is investigated via numerical simulations and experimental measurements. Two (2) experimental tools are used in combination to measure the velocity field in this study: 3D-Stereoscopic particles images velocimetry and 2D-laser doppler velocimetry. The numerical simulations are performed with steady RANS as well as URANS with the SST turbulence model. The results show the comparison of the turbulence intensity between experiments and CFD. Further assessment of the draft tube inlet flow is made with LDV to assess the circumferential non-uniformity of the flow. Finally, a complete frequency analysis puts in evidence the helical vortex rope frequency at partial discharge among many other flow phenomena. This study considered three operating points of a propeller axial turbine.Copyright © 2010 by ASME