In this current study, the transient numerical calculations using CFD code are carried out under different outlet impeller diameters for the flow field within a centrifugal pump under single-phase and cavitation conditions. Both qualitative and quantitative analyses are carried out on all of these results in order to better understand the flow structure within a centrifugal pump. Also, the investigations using different outlet impeller diameters configurations relating to the static pressure, velocity magnitude, vapour volume fraction variations, as well as pressure fluctuations in both time and frequency domain at the impeller and volute of the pump are analysed. Velocity and static pressure variations of the pump under different outlet impeller diameters range (200, 210 and 220 mm) are investigated. Reliable model is developed and validated, at various pump operating conditions, to analyse the characteristics of pressure fluctuations in both time and frequency domain. Cavitation occurrence, under different outlet impeller diameters and flow rates, are detected and correlated, using a CFD model (volume fraction distributions). Based on the developed model’s findings, at the set operating conditions ranges, the distribution and impact (cavitation and head-wises) of both the pressure and velocity are analysed. The average pressure fluctuation in the volute for do = 210 mm is higher than for do = 200 mm by about 6.74%, also the maximum pressure fluctuation for do = 220 mm is higher than for do = 210 mm by around 7.4%. Furthermore, the maximum pressure fluctuation in the impeller for do = 210 mm is higher than for do = 200 mm by 12.48%, also for do = 220 mm is higher than for do = 210 mm by 10.8%. The developed CFD models are proved valuable tools in identifying and optimizing the pump performance and characterization. The head for when do = 220 mm is higher than for when do = 200 mm under both single-phase and cavitation conditions by around 14.13% and 14.69%. The maximum pressure fluctuation for do = 200 mm is lower than for do = 210 mm by 41.58%. Furthermore, the maximum pressure fluctuation at the impeller for do = 220 mm is higher than the two models. There is a small clearance between the impeller and the volute for this model, leading to the pressure fluctuation amplitudes being higher than the other above models.
The authors wish to gratefully acknowledge in this current analysis, the authors want to acknowledge both the Mustansiriyah University, Baghdad, Iraq (www.uomustansiriyah.edu.iq) for their support.
Author contribution: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.
Research funding: None declared.
Conflict of interest statement: The authors declare no conflicts of interest regarding this article.
 B. P. Kamiel, Vibration-Based Multi-Fault Diagnosis for Centrifugal Pumps, Curtin, Curtin University, 2015.Search in Google Scholar
 A. R. Al-Obaidi, “Detection of cavitation phenomenon within a centrifugal pump based on vibration analysis technique in both time and frequency domains,” Exp. Tech., vol. 44, no. 3, pp. 329–347, 2020. https://doi.org/10.1007/s40799-020-00362-z.Search in Google Scholar
 A. R. Al-Obaidi and H. Towsyfyan, “An experimental study on vibration signatures for detecting incipient cavitation in centrifugal pumps based on envelope spectrum analysis,” J. Appl. Fluid Mech., vol. 12, no. 6, pp. 2057–2067, 2019. https://doi.org/10.29252/jafm.12.06.29901.Search in Google Scholar
 T. Okada, Y. Iwai, S. Hattori, and N Tanimura, “Relation between impact load and the damage produced by cavitation bubble collapse,” Wear, vol. 184, no. 2, pp. 231–239, 1995. https://doi.org/10.1016/0043-1648(94)06581-0.Search in Google Scholar
 J. Jensen and K. Dayton, Detecting Cavitation in Centrifugal Pumps, ORBIT, Second quarter, 2000, p. 5.Search in Google Scholar
 A. R. Al-Obaidi and I. Chaer, “Study of the flow characteristics, pressure drop and augmentation of heat performance in a horizontal pipe with and without twisted tape inserts,” Case Stud. Therm. Eng., vol. 25, p. 100964, 2021. https://doi.org/10.1016/j.csite.2021.100964.Search in Google Scholar
 J. Kim, K. T. Oh, K. B. Pyun, C. K. Kim, Y. S. Choi, and J. Y. Yoon, “Design optimization of a centrifugal pump impeller and volute using computational fluid dynamics,” IOP Conf. Ser.: Earth Environ. Sci., vol. 15, no. 3, p. 032025, 2012.10.1088/1755-1315/15/3/032025Search in Google Scholar
 R. Sidhesware and O. Hebbal, “Validation of hydraulic design of a metallic volute centrifugal pump,” Int. J. Eng. Res. Technol., pp. 2278–0181, 2013.Search in Google Scholar
 R. L. Kagami, E. LuizZaparoli, and C. R. de Andrad, “CFD analysis of an automotive centrifugal pump,” in 14th Brazilian Congress of Thermal Sciences and Engineering, 2012, p. 4.Search in Google Scholar
 S. Chakraborty, P. Dutta, and B. Debbarma, “Performance prediction of centrifugal pumps with variations of blade number,” J. Sci. Ind. Res., vol. 72, pp. 373–378, 2013.Search in Google Scholar
 M. Gupta, S. Kumar, and A. Kumar, “Numerical study of pressure and velocity distribution analysis of centrifugal pump,” Int. J. Tumor Ther., vol. 1, no. 1, pp. 117–121, 2011.Search in Google Scholar
 S. Chakraborty and K. Pandey, “Numerical studies on effects of blade number variations on performance of centrifugal pumps at 4000 RPM,” Int. J. Eng. Technol., vol. 3, no. 4, p. 410, 2011. https://doi.org/10.7763/ijet.2011.v3.262.Search in Google Scholar
 W. Shi, L. Zhou, W. Lu, B. Pei, and T. Lang, “Numerical prediction and performance experiment in a deep-well centrifugal pump with different impeller outlet width,” Chin. J. Mech. Eng., vol. 26, no. 1, pp. 46–52, 2013. https://doi.org/10.3901/cjme.2013.01.046.Search in Google Scholar
 F. Zhang, S. Yuan, Q. Fu, F. Hong, and J. Yuan, “Investigation of transient flow in a centrifugal charging pump during charging operating process,” Adv. Mech. Eng., vol. 6, p. 860257, 2014. https://doi.org/10.1155/2014/860257.Search in Google Scholar
 M. K. Abbas, “Cavitation in centrifugal pumps,” Diyala J. Eng. Sci. vol. 8716, pp. 22–23, 1999.Search in Google Scholar
 M. J. Kim, H. B. Jin, and W. J. Chung, “A study on prediction of cavitation for centrifugal pump,” in Proceedings of World Academy of Science, Engineering and Technology, World Academy of Science, Engineering and Technology (WASET), 2012, pp. 612–617.Search in Google Scholar
 W. Li, X. Zhao, W. Li, W. Shi, L. Ji, and L. Zhou, “Numerical prediction and performance experiment in an engine cooling water pump with different blade outlet widths,” Math. Probl Eng., vol. 2017, 2017, Art no. 8945712. https://doi.org/10.1155/2017/8945712.Search in Google Scholar
 W. Sun and L. Tan, “Cavitation-vortex-pressure fluctuation interaction in a centrifugal pump using bubble rotation modified cavitation model under partial load,” J. Fluid Eng., vol. 142, no. 5, p. 051206, 2020. https://doi.org/10.1115/1.4045615.Search in Google Scholar
 M. Liu, L. Tan, and S. Cao, “Influence of geometry of inlet guide vanes on pressure fluctuations of a centrifugal pump,” J. Fluid Eng., vol. 140, no. 9, p. 091204, 2018. https://doi.org/10.1115/1.4039714.Search in Google Scholar
 M. Liu, L. Tan, and S. Cao, “Method of dynamic mode decomposition and reconstruction with application to a three-stage multiphase pump,” Energy, vol. 208, p. 118343, 2020. https://doi.org/10.1016/j.energy.2020.118343.Search in Google Scholar
 M. Liu, L. Tan, and S. Cao, “Dynamic mode decomposition of gas–liquid flow in a rotodynamic multiphase pump,” Renew. Energy, vol. 139, pp. 1159–1175, 2019. https://doi.org/10.1016/j.renene.2019.03.015.Search in Google Scholar
 M. Liu, L. Tan, Y. Xu, and S. Cao, “Optimization design method of multi-stage multiphase pump based on Oseen vortex,” J. Petrol. Sci. Eng., vol. 184, p. 106532, 2020. https://doi.org/10.1016/j.petrol.2019.106532.Search in Google Scholar
 Y. Yang, L. Zhou, J. Hang, D. Du, W. Shi, and Z. He, “Energy characteristics and optimal design of diffuser meridian in an electrical submersible pump,” Renew. Energy, vol. 167, pp. 718–727, 2021. https://doi.org/10.1016/j.renene.2020.11.143.Search in Google Scholar
 Y. Yang, L. Zhou, W. Shi, Z. He, Y. Han, and Y. Xiao, “Interstage difference of pressure pulsation in a three-stage electrical submersible pump,” J. Petrol. Sci. Eng., vol. 196, p. 107653, 2021. https://doi.org/10.1016/j.petrol.2020.107653.Search in Google Scholar
 A. R. Al-Obaidi and R. Mishra, “Experimental investigation of the effect of air injection on performance and detection of cavitation in the centrifugal pump based on vibration technique,” Arabian J. Sci. Eng., vol. 45, no. 7, pp. 5657–5671, 2020. https://doi.org/10.1007/s13369-020-04509-3.Search in Google Scholar
 A. Fluent, 12.0 Theory Guide, New York, Ansys Inc, 2009, p. 5.Search in Google Scholar
 G. Pavesi, Impeller Volute and Diffuser Interaction, New York, DTIC Document, 2006.Search in Google Scholar
 A. R. Al-Obaidi, Experimental comparative investigations to evaluate cavitation conditions within a centrifugal pump based on vibration and acoustic analyses techniques, Arch. Acoust., vol. 45, pp. 541–556, 2020.Search in Google Scholar
 H.-l. Liu, D.-X. Liu, Y. Wang, et al.., “Application of modified κ–ω model to predicting cavitating flow in centrifugal pump,” Water Sci. Eng., vol. 6, no. 3, pp. 331–339, 2013.Search in Google Scholar
 Z. Li and T. Terwisga, “On the capability of multiphase RANS codes to predict cavitation erosion,” in Second International Symposium on Marine Propulsors, 2011, p. 8.10.3850/978-981-07-2826-7_113Search in Google Scholar
 A. R. Al-Obaidi, “Analysis of the effect of various impeller blade angles on characteristic of the axial pump with pressure fluctuations based on time-and frequency-domain investigations,” Iran. J. Sci. Technol. - Trans. Mech. Eng., vol. 45, no. 2, pp. 441–459, 2021. https://doi.org/10.1007/s40997-020-00392-3.Search in Google Scholar
 A. R. Al‐Obaidi, “Investigation of the flow, pressure drop characteristics, and augmentation of heat performance in a 3D flow pipe based on different inserts of twisted tape configurations,” Heat Transfer, vol. 50, pp. 5049–5079, 2021. https://doi.org/10.1002/htj.22115.Search in Google Scholar
 A. R. Al-Obaidi, “Experimental investigation of cavitation characteristics within a centrifugal pump based on acoustic analysis technique,” Int. J. Fluid Mech. Res., vol. 47, no. 6, pp. 501–515, 2020. https://doi.org/10.1615/interjfluidmechres.2020029862.Search in Google Scholar
 J. M. Cimbala, Fluid Mechanics: Fundamentals and Applications, vol. 1, New York, Tata McGraw-Hill Education, 2006.Search in Google Scholar
 A. R. Al-Obaidi, “Numerical investigation on effect of various pump rotational speeds on performance of centrifugal pump based on CFD analysis technique,” Int. J. Model. Simul. Sci. Comput., vol. 12, p. 2150045, 2021. https://doi.org/10.1142/s1793962321500458.Search in Google Scholar
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