Modelling of Work of the Rotor-Type Blade Pump with Revolving Stator

In the article, the analytical dependences of modelling the cell cross-sectional area between two adjacent blades of a rotary blade pump and capacity for a pump with fixed and rotating stators are given, and analytical dependences are derived to model the power necessary to overcome the friction forces of the blades. The forces acting on the radially placed blade of a rotary pump with a fixed stator (non-rotating or stationary) and a rotating stator are analyzed. Design and technological parameters that influence the pump capacity and power are taken into account. The power required for the movement of the pump blade without taking into account the compression of the air has the opposite character of the change as to the pump capacity The capacity of a rotary pump with a rotating stator is three times higher than that of a stationary stator. The rotary pump with a rotating stator, with six radially spaced blades, consumes 0.854 [kW] less power to overcome the blade friction of 1 313 [kW]. The results of modelling of the pump work are given.

Pressure and Flow Rate Fluctuations in Single- and Two-Blade Pumps

A comparative study on the highly unsteady flow field in single- and two-blade pumps is performed. Stationary pump characteristics, as well as pressure and flow rate fluctuations, are presented. Wall pressure fluctuations were measured in the suction and pressure pipe as well as at several locations within the volute casing by piezoresistive transducers. Flow rate fluctuations were evaluated by a recently presented measurement system based on an electromagnetic flowmeter (Melzer et al. 2020, “A System for Time-Fluctuating Flow Rate Measurements in a Single-Blade Pump Circuit,” Flow Meas. Instrum., 71, p. 101675). Measurements were accompanied by three-dimensional (3D) flow simulations with the open-source cfd software foam-extend. A thorough grid study and validation of the simulation were performed. By a complementary analysis of measurement and simulation results, distinctive differences between both pump types were observed, e.g., flow rate and pressure fluctuation magnitudes are significantly higher in the single-blade pump. In relation to the respective mean values, flow rate fluctuation magnitudes are one order lower than pressure fluctuation magnitudes for both pumps. For the two-blade pump, fluctuations attenuate toward overload irrespective of the particular pump circuit, while they rise for the single-blade pump. 3D simulation results yield detailed insight into the spatially and temporally resolved impeller–volute interaction and reveal that the single-blade impeller pushes a high-pressure flow region forward in a way as a positive displacement pump, resulting in an inherently fluctuating velocity and pressure distribution within the volute.

Approach to 3D Unsteady CFD Analysis of a Single-Blade Pump

Single-blade centrifugal pumps are hydraulic machines used in many industrial areas. A unique screw shaped blade enables liquids containing solids and fibrous matters to be pumped. Owing to good pump hydraulic properties on the one hand and unfavourable impeller mechanical properties on the other have single-blade pumps become recently more interesting for researchers regarding the CFD simulations. In this case a conventional CFD approach for multi-blade pumps cannot be applied due to the lack of symmetry of the single-blade impeller. Possible approaches to the CFD simulation of a single-blade impeller in the Ansys Fluent and the Ansys CFX are compared in this paper. A comparison of two CFD meshing tools showed substantial element number decrease of the whole CFD model. This paper presents also the laboratory experiment results of the investigated single-blade pump. The paper describes a new approach to the single-blade CFD simulation through Ansys Fluent which is faster and more user-friendly then the conventional approach.

Visualizing Test on the Distribution Rule of Coarse Particles in a Double Blade Pump

As a typical fluid mechanics problem, pump blockage has always been a hot research topic. The obtaining of the distribution of coarse particles in the solid-liquid two-phase flow pump is the basis of improving its non-blocking performance. High-speed photography technique is applied to do visualizing test and research on the distribution of coarse particles in a double blade pump. The effects of particle concentration, particle density and particle diameter on the distribution of coarse particles in the solid-liquid two-phase flow pump at different phases are studied. Besides, the variation of hydraulic performance of the double blade pump under different parameters is also analyzed. The results show that the particles in the impeller mainly located in the vicinity of the blade pressure surface, and the distribution of the particles in each section of the volute is quite different. The great difference in particle density can result in obviously uneven distribution of particles. With the increase of particle diameter, particle density and particle concentration, the pump head and efficiency both decrease while the shaft power increase on the contrary. This research results can also provide a basis for the optimization design of solid-liquid two-phase flow pumps.

The Optimization on Grid Division Methods of Blade Pump Blades Based on CFD

Grid division is the geometric expression forms and vectors of CFD numerical simulation engineering problems. The quality of the grid has an important impact on the CFD accuracy and computational efficiency about CFD. In this paper, it compares the structured and non-structured grid process summary base on blade pump. During a large number of mechanical fluid grid division and performance calculations, and combining with the theoretical guidance based on rotating machinery fluid Dynamics calculations, it summarizes some experience and practice on blades grid division optimization.

Numerical Analysis of Pressure Fluctuation Intensity for a Low-Speed Sewage Centrifugal Pump

Sewage centrifugal pumps can operate at different flow rates with variable rotating speeds to meet different performance requirements and achieve certain energy consumption criteria in pipeline systems. In this paper, the unsteady pressure field has been investigated numerically by CFD calculation to evaluate the transient pressure variation in a single-blade pump running with low rotating speeds. Based on the CFD results, the pressure fluctuation intensity was analyzed quantitatively by defining the standard deviation of the pressure fluctuation of a revolution period. The analysis of the results shows that the flow rate can influence the fluctuation intensity distribution obviously, and the same intensity distribution law can be found in the volute domain for the same flow rates with different rotating speeds. Obvious asymmetrical distributions can be observed in both front and back side chamber channels, and the pressure fluctuation intensity in back side chamber is weaker than in front side chamber. This work can obtain the knowledge of unsteady pressure phenomenon for typical flow rates in the low-speed running single-blade pump and can provide basis to optimize and to obtain more reliable pump at variable rotating speeds.