Investigations on the effect of tip clearance gap and inducer on the transport of air-water two-phase flow by centrifugal pumps. (8th June 2020)

• Record Type: Journal Article
• Authors: Parikh, Trupen; Mansour, Michael; Thévenin, Dominique
• Is Part Of: Chemical engineering science. Volume 218(2020)
• Publication Date: 2020-06-08
• Subjects: Centrifugal pumps -- Pump inducer -- Gas-liquid two-phase flow patterns -- Computational Fluid Dynamics (CFD) -- Volume of Fluid model (VOF); Chemical engineering -- Periodicals; Génie chimique -- Périodiques; Chemical engineering; Periodicals; Electronic journals; 660
• DOI: 10.1016/j.ces.2020.115554
• Languages: English
• ISSNs: 0009-2509

Abstract

Highlights: Two-phase flows were studied experimentally and numerically in a centrifugal pump. The ability of simulations to accurately predict all flow features was analyzed. Influence of the tip clearance gap and inducer on the performance were studied. Two-phase regimes and BSDs were identified with a high-speed camera. Increasing the gap or adding the inducer improved two-phase mixing and BSDs. Abstract: This study presents numerical and experimental investigations on air-water flows in a centrifugal pump. The objectives are to examine the accuracy of common numerical models, and to explain the influence of installing an inducer or increasing the tip clearance gap on the performance. 3D transient simulations were performed using the Volume of Fluid (VOF) method for two-phase modeling, and the k - ω SST model for turbulence modeling. The simulations agrees well with the experiments. However, the sudden head drop occurring at 5% gas content could not be predicted. Overall, the averaged relative errors between the simulations and the experiments for part-load, optimal, and overload conditions amount to 4%, 10% and 45%, respectively. The use of the inducer or increasing the gap leads to improvements in performance and phase mixing. Finally, bubble size distributions were analyzed using shadowgraphy, confirming that the inducer and the increased gap provide finer bubbles with narrower distributions.