Investigation of Recirculation Effects on the Formation of Vapor Bubbles in Centrifugal Pump Blades

Authors: Mohammad Taghi Shervani Tabar, Seyyed Hojjat Majidi, Zahra Poursharifi

Abstract:

Cavitation in pumps is known as the formation of vapor bubbles due to pressure drop and collapsing these bubbles. In some conditions, it has been observed that the formation of bubbles occurs at the pressure side of centrifugal pump blades. In this study, the formation of bubbles at the pressure side of blades has been investigated. Water is used in this study as the fluid and performance curves were depicted for different flow rates in an approximately constant speed. The results show that when a centrifugal pump works in low flow rates, a secondary flow namely recirculation starts to begin. In this condition, separation of flow increases which causes vortex formation and local pressure drop and eventually the formation of vapor bubbles starts.

Keywords: Cavitation, Centrifugal pump, Recirculation, Vapor bubble.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1073593

References:

[1] J.F., G├╝lich, "Selection criteria for suction impellers of centrifugal pumps", J. World Pumps, January 2001; 28- 34.
[2] A.J., Stepanoff, "Centrifugal and Axial Flow Pumps", John Wiley & Sons, 1948.
[3] P., Girdhar, and O.Moniz , "Practical Centrifugal Pumps: Design, Operation and Maintenance", Newnes- Elsevier, 2005.
[4] A.Nourbakhsh, A.Jaumotte, Ch.Hirsch, and Parizi H. B., "Turbopumps and Pumping Systems", Springer, 2008.
[5] R.Mackay , "Pump Clinic 3: What is Recirculation and Seperation", Kelair Pumps, May 2006.
[6] H.Frazer, "Flow Recirculation in Centrifugal Pumps", presented at the ASME Meeting, 1981.
[7] R.Mackay, "Low flow does not have to mean low reliability", J. World Pumps, July 2005; 22-25.