Numerical and experimental characterization of splitter blade impact on pump as turbine performance (original) (raw)
Related papers
IJERT-An Overview of Effect of Splitter Blades on Centrifugal Pump Performance
International Journal of Engineering Research and Technology (IJERT), 2013
https://www.ijert.org/an-overview-of-effect-of-splitter-blades-on-centrifugal-pump-performance https://www.ijert.org/research/an-overview-of-effect-of-splitter-blades-on-centrifugal-pump-performance-IJERTV2IS110882.pdf In turbomachinery design like pumps and compressors impeller is crucial part. The performance of the pump is depending upon the design of an impeller. It includes various parameters like blade inlet & outlet angle, impeller inlet & outlet diameter and number of blades. Increasing thenumber of blades increases the head of the pumpbut it causes a decrease in efficiency. The decrease in efficiency is due to the blockage of the fluid due to reduced area and increased friction inside the casing. Hence impeller with splitter blades can be used which reduces the clogging at impeller inlet. This addition of the splitter blades leads to increase the performance of the pump. As the splitter blade length increases; the flow rate and power increases, the efficiency decrease. As well as hydraulic performances are improved, pressure fluctuations are reduced, and operating range is extended. In this paper overview of various works are done. This paper tries to give an idea about the previous researches & their finding about study of effect of splitter blades on the centrifugal pump performance.
Theoretical Model to Predict the Performance of Centrifugal Pump Equipped with Splitter Blades
This study presents the results of the theoretical model to predict the centrifugal pump performance when its impeller is equipped with splitters. The proposed methodology accounts for the constructional differences of the pump equipped with splitter blades as compared with the conventional pump. For flow through axial blade rings, there is a distinct influence of the solidity on the outflow angle from the blades. This analogy is used for the derivation of a slip factor for impellers with splitters. A loss analysis procedure has been presented to predict the performance of centrifugal pumps. The result is compared with available experimental results. The predicted values of head over the operating range of flow rate of the pump have been found to be in reasonable agreement with the measurements.
CFD simulation on centrifugal pump impeller with splitter blades
Revista Brasileira de Engenharia Agrícola e Ambiental
The present paper aims to present the analysis and comparison of results of computational simulations using Computational Fluids Dynamics (CFD) in impellers of centrifugal pump. Three impellers were simulated: 1) original impeller, 2) original impeller with splitter blades at outlet; 3) original impeller with splitter blades at inlet. The splitters occupied 30% of the length of the main blades. They were simulated using the ANSYS-CFX software system in 1500 rpm rotational speed and at different flow rates. The turbulence model assumed was the Shear Stress Transport (SST). The results were used to build impeller blade head curves, besides the presentation of pressure distribution and streamline behaviour inside the impeller. It was verified that the insertion of the splitter blades reduced the impeller blade head, mainly the impeller with outlet splitter, whose reduction was more intense.
Journal of Applied Fluid Mechanics, 2020
Centrifugal pumps are among the most applicable machines in a wide variety of industrial systems for fluid pumping and transportation. Therefore their optimization has always been of great importance. Pump impellers play an important role in these machines as the energy transfer takes place in this part. In the present study, the impeller of a centrifugal pump is optimized by investigating the effect of adding splitter blades and modifying their geometry. A centrifugal pump is experimentally tested and numerically simulated and the characteristic curves are obtained. In the first stage, two different sets of splitter blades with different lengths are added to the impeller and the effect of splitter blade lengths on the results are explored. The case with the highest total head and overall efficiency is selected for the optimization process. The main blade and the splitter blade leading edge position and also the splitter blade distance between two successive blades are selected for the optimization process in the second stage. Efficiency and total head of the pump are considered as the optimization objectives. Using Design of Experiment (DoE) technique, the design space is created and response surface method is utilized to find the optimum geometry. The results show adding splitters can improve total head by about 10.6% and by modifying the geometry using DoE technique it could increase further by 4.4% with the negligible effect on the pump overall efficiency.
Effect of Blade Number on the Performance of a Centrifugal Pump Using Commercial Tool ANYS 91.2
IJRIAS, 2023
Computational fluid dynamics (CFD) is frequently used in centrifugal pump design. The characteristics of the flow fields around turbomachinery can be simulated using tools for numerical computational fluid dynamics in three dimensions. Numerical simulation, which also provides significant information for the hydraulic design of the centrifugal pump, can be used to visualize the internal flow condition of a centrifugal pump. The purpose of this study was to examine the effect of blade number on the hydraulic performance curve using a commercial instrument. ANSYS 91.2. code commercial.The geometric model of the pump was built using CF turbo, and the flow domain was meshed using the commercial programme ICEM. The results demonstrated that an increase in the number of blades significantly improved the hydraulic performance of the centrifugal pump's head. The findings also revealed that the area of the low-pressure zone at the blade's input suction grew and that the static pressure distribution homogeneity in the diffusion section was significantly better than that in the spiral section. The design flow of 35 m3 per hour is where the best efficiency point (BEP) is located. At Z = 6 and Z = 7, the head values were 51.58 m and 53.13 m, respectively, while the efficiency values were 50.32% and 53.35%. The comparison of the H-Q curve for estimated head discharge indicates that all impeller efficiency curves share the same fundamental tendency.
Optimizing Centrifugal Pump Performance by Different Blade Configuration Patterns
American Journal of Mechanical and Industrial Engineering, 2018
Impeller blades configuration is directly affecting the performance of the pump. Using splitter blades are one of the techniques that used to improve hydraulic performance. These modifications in the blades design are greatly affecting the dynamic performance of the pump. Splitting the blade changes its center of mass and makes it out of alignment with the center of rotation leading to eccentricity problem. The present research elucidates the effect of changing the blades configurations on both of hydraulic and dynamic performances. The impeller under study was designed such that, its shape could be changed using the splitting technique. The conventional blade could be defined as a baseline reference. Moreover, three additional configurations resulted from splitting impeller blades is hydraulically and dynamically investigated. The changes in flow rates, heads, and vibrations associated with each case were recorded and compared with the conventional case. Therefore the main results were clearly indicated as, the highest value of the pump maximum efficiency recorded for 3 rd configuration (as the middle and the outer parts staggered at 24° and 48° backward), where the lowest value for 1 st configuration (as the inner part of the blade staggered at 24° forward). On the other hand, the results showed that, splitting the impeller blade's leads to uneven distribution of masses around the impeller thus leading to unbalance problem. Moreover, Vibration increased as the extent of blades locations deviations increased. Therefore, to avoid unbalance problem the splitting the impeller blades have to be in urgently and narrowest uses, such as to decrease cavitation occurrence, this may be the important recommendation.
Assessment Performance of Pumps as Hydro-Turbines
The basic principle work of hydro-turbines are reversal of pumps, therefore, an alternative solution that can be developed in overcoming problem to get hydro turbines are by using pumps, by flowing water in the reverse direction through in the pumps, as hydro turbines. Those are supported by availability of pumps widely in the market and have been mass-produced hence they were relatively cheap. The aims of this research are to determine performances of pumps as turbines -reverse pumps. This experiment assesses performance of two small pumps that are centrifugal 'diffuser-pump' and 'volute-pump' as hydro turbines with various debit and head of water flow resource, such as output-powers and their efficiencies. The results show that the centrifugal diffuser-pump as hydro turbine performs maximum efficiency about 20,6%, where is as pump from its brochure suppose 47%. In the other hand, the centrifugal volute-pump as turbine achieves maximum efficiency about 32%, where is expected 26% as pump from its brochure. Both type of the pumps present that the maximum efficiency as turbines performed at head of water flow resource through the pumps as high as their maximum characteristic head of the pumps. Furthermore, both pumps as turbines generate high shaft revolution that was about 1.500 rpm at their maximum efficiency. Although those efficiencies are considerably low to an ideal efficiency 100%, however, the volute-pump as turbine performs a reasonably efficiency (32%) that higher than (at least is same as) the efficiency of its pump characteristic (26%), and this pump available very widely in the market. Should be pointed out that bigger dimension pumps propose higher efficiency up to about 86%, therefore they are expected to give higher efficiency as well. So, centrifugal volute-pumps are potential alternative solution to be used as hydro turbines.
Improvement of centrifugal pump performance through addition of splitter blades on impeller pump
The workable way to improve pump performance is to redesign or modify the impellers of centrifugal pump. The purpose of impeller pump modification is to improve pump efficiency, reduce cross flow, reduce secondary incidence flows, and decrease backflow areas at impeller outlets. Number blades and splitter blades in the impeller are three. The outlet blade angle is 20 o , and the rotating speed of impeller is 2400 rpm.The added splitter blades variations are 0.25, 0.375, and 0.5 of the original blade length. The splitter blade placements are on the outer side of the impeller. The addition of splitter blades on the outer side of the impeller with 0.5L increases the pump head until 22% and the pump has 38.66% hydraulic efficiency. The best efficiency point of water flow rate pump (Qbep) was 3.02 x 10-3 m 3 /s.
2015
The research on ̳pumps as turbines‘ at this critical phase of developing decentralized small hydro systems is appropriate for many reasons. The conventional turbine technologies like pelton and cross flow turbines that have been implemented in the micro hydro sector have to be custom-made and are therefore more expensive. They also need expert design and precise manufacturing skills for a good performance. This often becomes a bottleneck especially for smaller projects below 20 KWs of installed capacity. An alternative approach of using well-known ̳pump as turbine‘ technology can be contemplated and popularized. Pumps are readily available all over the world in every shape and size, mainly due to the ever-increasing demand for pumping application [7]. This research presents CFD based prediction of performance analysis of PAT for Dabis Hydro site which is located in West Shewa zone of Ethiopia, at 8°52'38.97" N latitude and 37°47'04.95" E longitude. According to sec...
Complex., 2021
Using a pump in reverse mode as a hydraulic turbine remains an alternative for hydropower generation in meeting energy needs, especially for the provision of electricity to remote and rural settlements. The primary challenge with small hydroelectric systems is attributed to the high price of smaller size hydraulic turbines. A specific commercial pump model, with a flow rate of 12.5 m3/h, head 32 m, pressure side diameter of 50 mm, impeller out, and inlet diameters of 160 mm and 6 mm, respectively, was chosen for this research. This research aimed to investigate a pump’s flow characteristics as a turbine to help select a suitable pump to be used as a turbine for micro- or small hydropower construction. Numerical methodologies have been adopted to contribute to the thoughtful knowledge of pressure and velocity distribution in the pump turbine performance. In this study, the unsteady flow relations amongst the rotating impeller and stationary volute of the centrifugal pump made up four...