Movement of Location of Tip Vortex Cavitation along Blade Edge due to Reduction of Flow Rate in an Axial Pump
Tip vortex cavitation is one of well known patterns of
cavitation phenomenon which occurs in axial pumps. This pattern of
cavitation occurs due to pressure difference between the pressure and
suction sides of blades of an axial pump. Since the pressure in the
pressure side of the blade is higher than the pressure in its suction
side, thus a very small portion of liquid flow flows back from
pressure side to the suction side. This fact is cause of tip vortex
cavitation and gap cavitation that may occur in axial pumps. In this
paper the results of our experimental investigation about movement
of tip vortex cavitation along blade edge due to reduction of pump
flow rate in an axial pump is reported. Results show that reduction of
pump flow rate in conjunction with increasing of outlet pressure
causes movement of tip vortex cavitation along blade edge towards
the blade tip. Results also show that by approaching tip vortex
cavitation to the blade tip, vortex tip pattern of cavitation replaces
with a cavitation phenomenon on the blade tip. Furthermore by
further reduction of pump flow rate and increasing of outlet pressure,
an unstable cavitation phenomenon occurs between each blade
leading edge and the next blade trailing edge.
[1] B. Schiavello and F. C. Visser, 2009, ÔÇÿ Pump Cavitation Various
NPSHR Criteria, NPSHA Margins, and Impeller Life Expectancy ÔÇÿ,
Proceedings of twenty-fifth international pump user symposium, Texas
A&M University.
[2] C. Brennen and A. J. Acosta, 1976, ÔÇÿThe Dynamic Transfer Function for
a Cavitating Inducer-, Journal of Fluids Engineering, Vol. 98,
Transactions of the ASME.
[3] A. B. Mitchell, 1958, ÔÇÿAn Experimental Investigation of Cavitation
Inception in the Rotor Blade Tip Region of an Axial Flow Pump -,
A.R.C. Technical Report, (21, 591), C.P. No.527, S.O. Code No. 23,
9012-27
[4] R. Laborde, P. Chantrel and M. Mory, 1997, "Tip clearance and tip
vortex cavitation in an axial flow pump", ASME J. Fluid. Eng.,
Vol.119.
[5] M. T. Shervani-Tabar and Z. Poursharifi, 2011, ÔÇÿAn Experimental Study
of Tip Vortex Cavitation Inception in an Axial Flow Pump -, World
Academy of Science, Engineering and Technology 73 2011
[6] Y. Tsujimoto, 2006, ÔÇÿFlow Instabilities in Cavitating and Non-
Cavitating Pumps Pumps-, In Design and Analysis of High Speed
Pumps (pp. 7-1 - 7-24). Educational Notes RTO-EN-AVT-143, Paper
7. Neuilly-sur-Seine, France: RTO. Available from:
http://www.rto.nato.int/abstracts.asp.
[1] B. Schiavello and F. C. Visser, 2009, ÔÇÿ Pump Cavitation Various
NPSHR Criteria, NPSHA Margins, and Impeller Life Expectancy ÔÇÿ,
Proceedings of twenty-fifth international pump user symposium, Texas
A&M University.
[2] C. Brennen and A. J. Acosta, 1976, ÔÇÿThe Dynamic Transfer Function for
a Cavitating Inducer-, Journal of Fluids Engineering, Vol. 98,
Transactions of the ASME.
[3] A. B. Mitchell, 1958, ÔÇÿAn Experimental Investigation of Cavitation
Inception in the Rotor Blade Tip Region of an Axial Flow Pump -,
A.R.C. Technical Report, (21, 591), C.P. No.527, S.O. Code No. 23,
9012-27
[4] R. Laborde, P. Chantrel and M. Mory, 1997, "Tip clearance and tip
vortex cavitation in an axial flow pump", ASME J. Fluid. Eng.,
Vol.119.
[5] M. T. Shervani-Tabar and Z. Poursharifi, 2011, ÔÇÿAn Experimental Study
of Tip Vortex Cavitation Inception in an Axial Flow Pump -, World
Academy of Science, Engineering and Technology 73 2011
[6] Y. Tsujimoto, 2006, ÔÇÿFlow Instabilities in Cavitating and Non-
Cavitating Pumps Pumps-, In Design and Analysis of High Speed
Pumps (pp. 7-1 - 7-24). Educational Notes RTO-EN-AVT-143, Paper
7. Neuilly-sur-Seine, France: RTO. Available from:
http://www.rto.nato.int/abstracts.asp.
@article{"International Journal of Mechanical, Industrial and Aerospace Sciences:63300", author = "Mohammad T. Shervani-Tabar and Navid Shervani-Tabar", title = "Movement of Location of Tip Vortex Cavitation along Blade Edge due to Reduction of Flow Rate in an Axial Pump", abstract = "Tip vortex cavitation is one of well known patterns of
cavitation phenomenon which occurs in axial pumps. This pattern of
cavitation occurs due to pressure difference between the pressure and
suction sides of blades of an axial pump. Since the pressure in the
pressure side of the blade is higher than the pressure in its suction
side, thus a very small portion of liquid flow flows back from
pressure side to the suction side. This fact is cause of tip vortex
cavitation and gap cavitation that may occur in axial pumps. In this
paper the results of our experimental investigation about movement
of tip vortex cavitation along blade edge due to reduction of pump
flow rate in an axial pump is reported. Results show that reduction of
pump flow rate in conjunction with increasing of outlet pressure
causes movement of tip vortex cavitation along blade edge towards
the blade tip. Results also show that by approaching tip vortex
cavitation to the blade tip, vortex tip pattern of cavitation replaces
with a cavitation phenomenon on the blade tip. Furthermore by
further reduction of pump flow rate and increasing of outlet pressure,
an unstable cavitation phenomenon occurs between each blade
leading edge and the next blade trailing edge.", keywords = "Axial Flow Pump, Cavitation, Gap Cavitation, Tip
Vortex Cavitation.", volume = "6", number = "1", pages = "338-5", }