Effects of Volute Curvature on Performance of a Low Specific-Speed Centrifugal Pump at Design and Off-Design Conditions

Abstract

The effects of the volute geometry on the head, efficiency, and radial force of a low specific-speed centrifugal pump were investigated focusing on off-design conditions. This paper is divided into three parts. In the first part, the three-dimensional flow inside the pump with rectangular volute was simulated using three well-known turbulence models. Simulation results were compared with the available experimental data, and an acceptable agreement was obtained. In the second part, two volute design methods, namely, the constant velocity and the constant angular momentum were investigated. Obtained results showed that in general the constant velocity method gives more satisfactory performance. In the third part, three volutes with different cross section and diffuser shape were designed. In general, it was found that circular cross section volute with radial diffuser provides higher head and efficiency. Moreover, the minimum radial force occurs at higher flowrate in circular volute geometry comparing to rectangular cross section volute.

Influence of Cross-Sectional Flow Area of Annular Volute Casing on Transient Characteristics of Ceramic Centrifugal Pump

“…They found that the pulsation in leakage through the impeller-tongue gap increased by 30% when the flow rate increased by 60% from the rated condition. Alemi et al [21] and Yang et al [22] reported the influence of cross-sectional shape on the hydraulic performance of a centrifugal pump and found that the circular cross sectional shape could provide a higher pump head and efficiency than trapezoidal and rectangle shapes. Bowerman et al [23], Chan et al [24], and Chang et al [25] reported that reducing the crosssectional area could offset the optimal efficiency point to a smaller flow rate condition and result in a steeper pressure fall at the pump outlet, specifically under large flow rate conditions.…”

Investigation of Blade Number Effect on Hydraulic Performance of In-Pipe Hydro Savonius Turbine

“…Modeling the fluid flow passing through the turbine is performed by using RANS equations. Among the turbulence models, the most suitable model to simulate turbomachines is the − model [34]. The − turbulence model is recommended by Menters [35][36][37] and has positive features of the − and − models simultaneously.…”

طراحی بهینه، ساخت و آزمون محفظه ی کمپرسور جریان شعاعی

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