Study of cavitation in hydro turbines—A review

Reaction turbines basically Francis turbines and propeller/Kaplan turbines are suitable for medium and low head hydropower sites. The management of the small hydropower plants is an important factor, for achieving higher efficiency of hydro turbines with time. Turbines show declined performance after few years of operation, as they get severely damaged due to various reasons. One of the important reasons is erosive wear of the turbines due to cavitation. Reaction turbines, however are more prone to cavitation especially Francis turbines where a zone in the operating range is seriously affected by cavitation and considered as forbidden zone. Cavitation is a phenomenon which manifests itself in the pitting of the metallic surfaces of turbine parts because of the formation of cavities. In the present paper, studies undertaken in this field by several investigators have been discussed extensively. Based on literature survey various aspects related to cavitation in hydro turbines, different causes for the declined performance and efficiency of the hydro turbines and suitable remedial measures suggested by various investigators have been discussed.

[1]  J.-M. Gagnon,et al.  Numerical Simulation With Flow FeatureExtraction Of A Propeller Turbine UnsteadyRotor-stator Interaction , 2007 .

[2]  Romeo Susan-Resiga,et al.  Scientific Bulletin of the "Politehnica" Univerity of timisoara, Romania, Transactions on Mechanics, Proceedings of the 6th International Conference on Hydraulic Machinery and Hydrodynamics, Timisoara, Romania, October 21-22, 2004 /R. Susan-Resiga,S. Bernad, S. Muntean, M. Popoviciu , 2004 .

[3]  Eduard Egusquiza,et al.  Cavitation Erosion Prediction in Hydro Turbines from Onboard Vibrations , 2004 .

[4]  Mahesh M. Athavale,et al.  Application of the Full Cavitation Model to Pumps and Inducers , 2002 .

[5]  Mie Sato,et al.  A case study in selective visualization of unsteady 3D flow , 2002, IEEE Visualization, 2002. VIS 2002..

[6]  Christophe Nicolet,et al.  Influence of the vortex rope location of a Francis Turbine on the hydraulic system stability , 2008 .

[7]  Bernd Nennemann,et al.  KAPLAN TURBINE BLADE AND DISCHARGE RING CAVITATION PREDICTION USING UNSTEADY CFD , 2007 .

[8]  M. Szkodo,et al.  Effect of laser heating on cavitation behaviour of Fe-Cr-Mn coating abstract , 2004 .

[9]  R. K. Rajput,et al.  Fluid Mechanics and Hydraulic Machines , 1998 .

[10]  François Avellan,et al.  Physical Investigation of the Cavitation Phenomenon , 2000 .

[11]  Mohamed Farhat,et al.  Improving Hydro Turbine Profitability by Monitoring Cavitation Aggressiveness , 1999 .

[12]  François Avellan,et al.  Identification and Modeling of Pressure Fluctuations of a Francis Turbine Scale Model at Part Load Operation , 2004 .

[13]  Eduard Egusquiza,et al.  Detection of cavitation in hydraulic turbines , 2006 .

[14]  Christophe Nicolet,et al.  Methodology for Risk Assessment of Part Load Resonance in Francis Turbine Power Plant , 2006 .

[15]  M. Grekula,et al.  Experimental Study of Cavitation in a Kaplan Model Turbine , 2001 .

[16]  Sebastian Muntean,et al.  Development of a Swirling Flow Control Technique for Francis Turbines Operated at Partial Discharge , 2007 .

[17]  Branko Bajić.  Multidimensional Diagnostics of Turbine Cavitation , 2002 .

[18]  Branko Bajic.  Methods for vibro-acoustic diagnostics of turbine cavitation , 2003 .

[19]  Ching-Jen Chen,et al.  The 9th international symposium on fluid control, measurement and visualization (FLUCOME 2007) , 2008, J. Vis..

[20]  Håkan Nilsson,et al.  A numerical investigation of tip clearance flow in Kaplan water turbines , 1999 .

[21]  François Avellan,et al.  Comparison of erosion mechanisms in different types of cavitation , 1986 .

[22]  François Avellan,et al.  Introduction to Cavitation in Hydraulic Machinery , 2004 .