Influence of the Blade Trailing Edge Profile on the Performance and Unsteady Pressure Pulsations in a Low Specific Speed Centrifugal Pump

Effects of modifying the blade trailing edge profile on unsteady pressure pulsations and flow structures in a centrifugal pump

Experimental Investigation on Unsteady Pressure Pulsation in a Centrifugal Pump With Special Slope Volute

Performance evaluation of an axial-flow pump with adjustable guide vanes in turbine mode

DDES analysis of the unsteady wake flow and its evolution of a centrifugal pump

Numerical and Experimental Study of Unsteady Flow in a Large Centrifugal Pump With Stay Vanes

Purpose – The purpose of this paper is to analyze the ability of turbulence models to model the flow field in the runner of a Francis turbine. Although the complex flow in the turbine can be simulated by CFD models, the prediction accuracy still needs to be improved. The choice of the turbulence model is one key tool that affects the prediction accuracy of numerical simulations. Design/methodology/approach – This study used the SST k-w and RNG k-e turbulence models, which can both accurately predict complex flow fields in numerical simulations, to simulate the flow in the entire flow passage of a Francis turbine with the results compared against experimental data for the performance and blade pressure distribution in the turbine to evaluate the applicability of the turbulence models. Findings – The results show that the SST k-w turbulence model more accurately predicts the turbine performance than the RNG turbulence model. However, the blade surface pressures predicted by the SST k-w turbulence model were...

Adaptability of turbulence models to predict the performance and blade surface pressure prediction of a Francis turbine

The pressure fluctuations in both the rotating runner and the other fixed components in a model Francis turbine under various loads were experimentally measured by means of onboard measuring equipment in the runner and data storage device on the shaft in this study. Large pressure fluctuation were observed under both small guide vane opening and large guide vane opening conditions. Flow separation at the blade suction surface led to large pressure fluctuations for small guide vane openings, the unsteady flow around the inlet on the blade pressure side led to large pressure fluctuations for large openings. The pressure fluctuations correlation between the runner and other components of the turbine, mainly the draft tube, was analyzed in detail for both small guide vane opening (12°) and large guide vane opening (30°). The results show that the pressure fluctuations in the runner space increased by the superposition of draft tube vortex rope pressure fluctuations and runner inter blade vortices pressure fluctuations, resulting in much larger pressure fluctuations in the runner space than in other components.

Experimental Study of the Francis Turbine Pressure Fluctuations and the Pressure Fluctuations Superposition Phenomenon Inside the Runner

The utility model relates to a centrifugal pump spiral case comprising an inner cavity and a separating tongue. The centrifugal pump spiral case is characterized in that two baffle plates are disposed in the inner cavity; the inner cavity is evenly divided into three spiral chambers via the two baffle plates and the separating tongue; and radial force of each spiral chamber is symmetrically distributed at 120 degrees, so the radial force can be balanced. The centrifugal pump spiral case can be widely applied to large centrifugal pumps with high lift and bulk flows.

Centrifugal pump spiral case

The invention relates to a centrifugal pump volute, which comprises an inner cavity and a dividing wall. The centrifugal pump volute is characterized in that two baffles are arranged in the inner cavity; the inner cavity is divided into three evenly distributed spiral housings by the two baffles and the dividing wall; radial forces generated by all the spiral housings are symmetrically distributed at an angle of 120 degrees, and thus, an effect that the radial forces are balanced can be exerted. The centrifugal pump volute provided by the invention can be widely applied to large centrifugal pumps in high-lift and high-flow pump stations.

Gao Zhongxin

Papers

Numerical and Experimental Study of Unsteady Flow in a Large Centrifugal Pump With Stay Vanes

Adaptability of turbulence models to predict the performance and blade surface pressure prediction of a Francis turbine

Experimental Study of the Francis Turbine Pressure Fluctuations and the Pressure Fluctuations Superposition Phenomenon Inside the Runner

Centrifugal pump spiral case

Centrifugal pump volute