Research Center for Engineering of
                Systems with Complex Fluids
Title: Flow-Feedback control tehnique for vortex rope mitigationfrom conical diffuser of hydrauylic turbines draft tube
Published In: Proceedings of the Romanian Academy, Series A: Mathematics, Physics, Technical Sciences, Informational Science, Volume 12, Number 2, pp. 125-132
Description: It is known that the hydraulic turbines operated at partial discharge (especially hydraulic turbines with fixed blades, i.e. Francis turbine), developing a central stagnant region in the conical diffuser of draft tube. As a result, the helical vortex breakdown, also known in the literature like “precessing vortex rope” is developed. It is shown by prof. Resiga that a water jet introduced axially through the runner crown mitigates the vortex rope and associated phenomena. However, numerical simulation and experimental measurements shown the control jet discharge is higher than 10% from main discharge. This fraction of water which bypasses the runner is taken into account like volumetric losses. Sometimes, this water fraction used to supply the jet is not valid. Consequently, this paper investigates a new flow control technique proposed by prof. Resiga which supplies the axial jet from downstream of the conical diffuser of hydraulic turbines. The water to supply the jet is driven by the pressure drop between cone wall and crown tip. This control technique is called “flow-feedback”.
ISBN: 
ISSN:ISSN: 1454-9069
DOI: 
Publication year: 2011
Keywords:Flow-feedback control technique, vortex rope conical diffuser, hydraulic turbines.
Download Paper: Paper
Authors: TANASA Constantin , BOSIOC Ilie Alin , MUNTEAN Sebastian , SUSAN-RESIGA Romeo ,
Type: International Journal Article
Link: http://www.acad.ro/sectii2002/proceedings/proc_pag2011_n02.htm
Laboratory: Numerical Simulation and Parallel Computing Laboratory
Institution: UPT