Research Center for Engineering of
                Systems with Complex Fluids
Title: Mitigation of pressure fluctuations in the discharge cone of hydraulic turbines using flow-feedback
Published In: IOP Conf. Series: Earth and Environmental Science 12 (2010) 012067
Description: Our previous experimental and numerical investigations of decelerated swirling flows in conical diffusers have demonstrated that water jet injection along the symmetry axis mitigates the pressure fluctuations associated with the precessing vortex rope. However, for swirling flows similar to Francis turbines operated at partial discharge, the jet becomes effective when the jet discharge is larger than 10% from the turbine discharge, leading to large volumetric losses when the jet is supplied from upstream the runner. As a result, we introduce in this paper a new approach for supplying the jet by using a fraction of the discharge collected downstream the conical diffuser. We present the technical implementation of this flowfeedback approach, and we investigated experimentally its capability in mitigating the pressure fluctuations generated by the precessing vortex rope. The main advantage of this flowfeedback approach is that is does not require additional energy to supply the jet and it does not decrease the turbine efficiency.
DOI:DOI: 10.1088/1755-1315/12/1/012067
Publication year: 2010
Keywords:Francis turbine, vortex rope, pressure fluctuations, pressure recovery coefficient, flow-feedback.
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Authors: TANASA Constantin , SUSAN-RESIGA Romeo , BOSIOC Ilie Alin , MUNTEAN Sebastian ,
Type: International Conference Proceedings
Laboratory: Numerical Simulation and Parallel Computing Laboratory
Institution: UPT