Test results for a low-speed centrifugal pump

1995 ◽  
Vol 31 (4) ◽  
pp. 189-192
Author(s):  
N. S. Yalovoi ◽  
A. M. Kats
2021 ◽  
Vol 13 (2) ◽  
pp. 168781402199811
Author(s):  
Wu Xianfang ◽  
Du Xinlai ◽  
Tan Minggao ◽  
Liu Houlin

The wear-ring abrasion can cause performance degradation of the marine centrifugal pump. In order to study the effect of front and back wear-ring clearance on a pump, test and numerical simulation were used to investigate the performance change of a pump. The test results show that the head and efficiency of pump decrease by 3.56% and 9.62% respectively at 1.0 Qd due to the wear-ring abrasion. Under 1.0 Qd, with the increase of the front wear-ring the vibration velocity at pump foot increases from 0.4 mm/s to 1.0 mm/s. The axis passing frequency (APF) at the measuring points increases significantly and there appears new characteristic frequency of 3APF and 4APF. The numerical simulation results show that the front wear-ring abrasion affects the flow at the inlet of the front chamber of the pump and impeller passage. And the back wear-ring abrasion has obvious effect on the flow in the back chamber of the pump and impeller passage, while the multi-malfunction of the front wear-ring abrasion and back wear-ring abrasion has the most obvious effect on the flow velocity and flow stability inside pump. The pressure pulsation at Blade Passing Frequency (BPF) of the three schemes all decrease with the increase of the clearance.


2021 ◽  
pp. 1-30
Author(s):  
Alejandro Castillo Pardo ◽  
Cesare A. Hall

Abstract Boundary Layer Ingestion (BLI) potentially offers significant reductions in fuel burn and pollutant emissions. The Propulsive Fuselage Concept features a fan at the back of the airframe that ingests the 360deg fuselage boundary layer. Consequently, the distortion at the fan face during cruise is close to radial. This paper aims to devise and test a fan design philosophy that is tuned to this inflow distortion. Initially a free-vortex fan design matched to clean inflow is presented. The effects of BLI on the aerodynamics of this fan are investigated. A series of design steps are then presented to develop the baseline fan into a new design matched to fuselage BLI inflow. Both fan designs have been tested within a low speed rig. The impact of the fan design changes on the aerodynamics and the performance with BLI are evaluated using the test results. This paper presents the successful application of a unique experimental facility for the analysis of BLI fuselage fans. It shows that it is possible to design a fan that accepts the radial distortion caused by fuselage BLI with a modified profile of work input. The new fan design was found to increase the work input by 4.9% and to improve the efficiency by 2.75% relative to a fan designed for clean flow. This new fan design has reduced loading near the hub to account for the incoming distortion, increased mid span loading and negative incidence towards the tip for tolerance to circumferential distortion off-design.


Author(s):  
Shouqi Yuan ◽  
Jinfeng Zhang ◽  
Yue Tang ◽  
Jianping Yuan ◽  
Yuedeng Fu

The research on a centrifugal pump of low specific speed with splitter blades was carried out in recent years by our group, is systematically introduced in this paper. The design method is summarized also. At the beginning, based on the former L9(34) orthogonal test, Particle Imagine Velocity (PIV) tests and Computational Fluid Dynamics (CFD) simulations were carried out for several designs with different splitter blade length. Results show that for an impeller with splitter blades the “jet-wake” flow at the impeller outlet is improved, and the velocity distribution inside the impeller is more uniform. This explains that the impeller with splitter blades shows higher performance (especially in head and efficiency). Meanwhile, the numerical simulation results were compared with the test results, which confirm that, CFD technology can be used to observe inner flow distribution and forecast pump performance tendency. Later, a further L9(34) orthogonal test, which adopt the blade number as a new variable, was designed to explore the relationship between geometry parameters of splitter blade and pump performance, and corresponding CFD simulations for the flow field with volute were also done. From the test results the influence of the main design parameters on the hydraulic performance of a centrifugal pump and its reasonable value range are determined. The simulations forecasted pump performance show good consistency with that from tests at the rated point, and the simulated error at other flow rates were analyzed. Thirdly, in order to save research cost, numerical simulations were done for the full flow field including the cavity inside the volute and impeller. By analyzing the distribution law of blade torque and turbulent kinetic energy in the impeller, the value fetching principle for the splitter blade inlet diameter is presented as “the splitter blades torque should be positive”, and by analyzing the distribution of blades loading, the flow distribution rules and pump performance influenced by different splitter blades off-setting angles and inlet diameters were discovered. The disk friction loss, which consuming much energy in centrifugal pumps, was also forecasted at various operating conditions. The results were compared with that from empirical formulas, which show great accordance at the rated point, and the forecasted results at off-design points were analyzed also. Finally, the research results and the design method for the centrifugal pump with splitter blades, such as how to select splitter blade number, the off-setting angle, the inlet diameter and the deflection angle, were summarized.


1978 ◽  
Vol 44 (378) ◽  
pp. 588-597 ◽  
Author(s):  
Hideo OHASHI ◽  
Norihiro YOSHIKAWA ◽  
Masuji MATSUMURA ◽  
Yukio KATSUMATA
Keyword(s):  

Author(s):  
Guidong Li ◽  
Yang Wang ◽  
Jieyun Mao

To investigate the influence of entraining and separating effect of gas–liquid two-phase on self-priming performance in the flow-ejecting centrifugal pump, three different schemes of adding the baffle plate behind the guide vane were proposed. Experiments on self-priming performance for three different guide vane schemes were carried out, and numerical calculations on entraining property in the ejector and separating property in the chamber were analyzed by means of the Eulerian–Eulerian multiphase flow model. Meanwhile, the frequency domain properties of pressure pulsation and the pump performance curves were obtained to further verify the feasibility of the scheme in practical application. The results show that the simulation analysis agreed well with the test results. The area and magnitude of high velocity region and vorticities in the ejector of scheme 2 are remarkably larger than those of other schemes. Gas–liquid separation efficiency in a pump chamber also significantly improves when the baffle plate behind the guide vane is mounted at an appropriate position. Furthermore, different guide vane schemes have certain impact on the characteristics of internal and unsteady flow pulsation phenomena in model pump but are within the acceptable operation range. The head and efficiency of scheme 2 are also slightly higher than those of the prototype in the full operation range.


Author(s):  
Takaharu Tanaka ◽  
Chao Liu

This paper presents a non-traditional perspective of energy transfer in turbomachinery. Two different kinds of energy are present. One is a kind of invisible imaginary storage energy that stores energy on the acted material and the other is a kind of visible real working energy that does not store the energy on the acted material but acts on the material to move it and do the work in the direction of action. Their acting directions are normal to each other. Their fundamental interrelation and the interrelation with the blade angle of centrifugal pump are theoretically discussed. Experimental test results are also shown in this paper.


Author(s):  
Peter Achten ◽  
Jeroen Potma ◽  
Jasper Achten

Low speed operation of axial piston motors has always been a critical performance issue. The breakaway torque determines the capacity of a motor to move a certain load from standstill conditions. In addition, the low speed performance has also become a critical performance parameter for pumps being applied in frequency controlled electro-hydraulic actuators. Yet, there is almost no information available about the low speed and breakaway characteristics of piston pumps and motors. A new test bench has been constructed to measure these characteristics [1]. The new bench allows operation of hydrostatic machines below 1 rpm, down to 0.009 rpm. At these conditions, the main tribological interfaces operate in the solid friction domain, at which the friction losses are at a maximum value. This research describes and analysis the test results for a number of different axial piston pumps and motors: two slipper type motors, one slipper type pump and a floating cup pump/motor. The tests have been performed at various operating pressures and operating speeds. Furthermore, the breakaway torque has also been measured after letting the hydrostatic motor stand still for one or more days.


1993 ◽  
Author(s):  
T. CRUM ◽  
D. YATES ◽  
T. ANDREW ◽  
N. STOCKMAN
Keyword(s):  

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