Shape Optimization of the Pick-Up Tube in a Pitot-Tube Jet Pump

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
J. Meyer ◽  
L. Daróczy ◽  
D. Thévenin
Keyword(s):  
Computer Aided Design ◽  
Characteristic Curve ◽  
Pitot Tube ◽  
Superior Performance ◽  
Jet Pump ◽  
Pump Design ◽  
Standard Design ◽  
Low Specific Speed ◽  
Specific Speed ◽  
The Impact

At a very low specific speed (VLSS), pumps normally suffer from high disk friction losses. In order to solve this issue, it can be helpful to use a different centrifugal pump design, which is not often found in the pump industry: the Pitot-tube jet pump (PTJ pump). It shows superior performance at low specific speed due to a rather unconventional working principle, described in detail in this paper. The key design feature of the PTJ pump is the (fixed) pick-up tube. Its geometry has not varied over the last decades; it is referred to in this study as “initial” or “standard” design configuration. However, optimizing the pick-up tube might lead to a considerably higher performance. Therefore, a parameterized three-dimensional (3D) computer-aided design (CAD) model is used in this study to investigate the impact of shape deformation on pump performance with the help of computational fluid dynamics (CFD). Two CFD approaches are presented and compared for this purpose: a computationally efficient approach with limited accuracy (low-fidelity method) and a more detailed, but computationally more expensive, high-fidelity approach. Using both approaches, it is possible to obtain highly efficient PTJ pumps. As a consequence, first design rules can be derived. Finally, the optimized design has been tested for various operation points, showing that the performance is favorably impacted along the complete characteristic curve.

Study on Electromagnetic Vibration Pump

2013 ◽  
Vol 774-776 ◽  
pp. 312-315
Author(s):  
Zhan Xiong Lu
Keyword(s):  
Research Field ◽  
Pump Design ◽  
Positive Displacement ◽  
Low Viscosity ◽  
Electromagnetic Vibration ◽  
Displacement Pump ◽  
Small Flow ◽  
Working Principle ◽  
Low Specific Speed ◽  
Specific Speed

Electromagnetic vibration pump is one type of first proposed new household positive displacement pump.It is mainly used to transport water and other low viscosity liquid. It has many advantages including small flow, high head, simple structure,good self-priming performance. Electromagnetic driving method was combined with displacement pump in vibration pump for the first time. Its specific speed can reach below 10,and this is a breakthrough in super-low specific speed pump design. The working principle of electromagnetic vibration pump and its performance were studied in the paper. each of these problems is further discussed and explained in order to point out the research field for the development of electromagnetic vibration pump later.

Experimental and Numerical Investigation of a Counter-Rotating Mixed-Flow Single Stage Pump

2015 ◽  
Author(s):  
Stefano Tosin ◽  
Jens Friedrichs ◽  
Andreas Dreiss
Keyword(s):  
Characteristic Curve ◽  
Speed Ratio ◽  
Centrifugal Pumps ◽  
Mixed Flow ◽  
Pump Design ◽  
Machine Performance ◽  
Novel Approach ◽  
Specific Speed ◽  
Definition Of ◽  
New Generation

A prototype of a new generation of centrifugal pumps has been developed, with aim to improve typical weaknesses like narrow operable range due to slip and incidence losses in off-design conditions. The peculiarity of this pump is the absence of any stator blade, which has been substituted with a counter-rotating radial impeller. According to an exhaustive literature survey, the usage of a mixed flow impeller as a front rotor, followed by a radial-flow impeller seems to be a novel approach in pump design. The combination of a high specific speed impeller with a low specific speed rotating diffuser produces a flexible adaptability against aforementioned limits. Keep on adding energy to the fluid instead of just diffusing the flow, permits to reach a downsized hydraulics and an increased entire machine power density. The characteristic of such a pump needs to be analyzed as 3D-surface, both speeds are actually independent and for a fixed discharge the head rise and efficiency become surfaces. A new definition of optimized characteristic curve, with variable speed ratio, could be identified based on those performance maps. A special test rig has been built to measure the machine performance, distinguishing the mechanical losses of both shafts separately with no-load measurements. The sensitivity of the system on speed ratio variation has been explored. The experiments show the presence of different best speed ratios which maximize alternately the head or the efficiency. Additionally, the results confirm the possibility to expand the working range acting on the rotational speeds. Head rise and efficiency curves with varying speed ratio, as functions of the flow rate are finally shown using several diagrams, highlighting the advantages of this new design.

Numerical and Experimental Study of Inner Flow and Hydraulic Performance of the Mixed-Flow Pump With Low Specific Speed

2018 ◽  
Author(s):  
Jianping Yuan ◽  
Meng Fan ◽  
Yanjun Li ◽  
Yanxia Fu ◽  
Rong Lu
Keyword(s):  
Rapid Development ◽  
Internal Flow ◽  
Fluctuation Analysis ◽  
Market Demand ◽  
Mixed Flow ◽  
Pump Design ◽  
Flow Rates ◽  
Low Specific Speed ◽  
Specific Speed ◽  
Flow Pump

Mixed flow pumps are very suitable for market demand with the rapid development of urbanization, especially for low specific speed mixed flow pumps which has been widely used in various fields [1–3]. In this study, the calculations of the incompressible 3D internal flow of the mixed-flow pump with low specific speed was carried out by using CFD technique based on the N-S equation coupled with the standard k-ε turbulence model at different flow rates. The hydraulic performances of the mixed-flow pump as well as the inner flow were analyzed in comparison with the corresponding experimental data. Meanwhile, the static pressure and relative velocity distribution on blades were studied at low, design as well as large flow rates, respectively. Finally, it can obtain that the predicted pump performance curves based on numerical simulation have a good agreement with the experimental results, which verify the numerical method applied in this work accurate in a certain extent. Furthermore, the results also provide some references to hydraulic forces and pressure fluctuation analysis and the performance improvement for the mixed-flow pump design.

Investigation of the impact of splitter blades on a low specific speed pump for fluid-induced vibration

2020 ◽  
Vol 34 (7) ◽  
pp. 2883-2893
Author(s):  
Guitao Zeng ◽  
Qianqian Li ◽  
Peng Wu ◽  
Bo Qian ◽  
Bin Huang ◽  
...  
Keyword(s):  
Low Specific Speed ◽  
Specific Speed ◽  
The Impact

scholarly journals The Role of Blade Sinusoidal Tubercle Trailing Edge in a Centrifugal Pump with Low Specific Speed

Processes ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 625 ◽  
Author(s):  
Bowen Li ◽  
Xiaojun Li ◽  
Xiaoqi Jia ◽  
Feng Chen ◽  
Hua Fang
Keyword(s):  
Centrifugal Pump ◽  
Pressure Pulsation ◽  
Suction Side ◽  
High Amplitude ◽  
Pressure Pulsations ◽  
Trailing Edge ◽  
Low Specific Speed ◽  
Specific Speed ◽  
And Performance ◽  
The Impact

Pressure pulsations may cause high-amplitude vibrations during the process of a centrifugal pump. The trailing edge shape of the blade has a critical influence on the pump’s pressure fluctuation and hydraulic characterization. In this paper, inspired by the humpback whale flipper, the authors research the impact of applying the sinusoidal tubercles to the blade suction side of the trailing edge. Numerical calculation and experiments are carried out to investigate the impact of the trailing edge shape on the pressure pulsations and performance of a centrifugal pump with low specific speed. Two designed impellers are tested, one is a sinusoidal tubercle trailing edge (STTE) impeller and the other is the original trailing edge (OTE) prototype. The detailed study indicates that the sinusoidal tubercle trailing edge (STTE) reduces pressure pulsation and enhances hydraulic performance. In the volute tongue region, the pressure pulsation amplitudes of STTE at fBPF decrease significantly. The STTE impeller also effectively changes the vortex structure and intensity in the blade trailing edge area. This investigation will be of great benefit to the optimal design of pumps.

scholarly journals Analysis of the influence of a stator type modification on the performance of a pump with a hole impeller

2019 ◽  
Vol 9 (1) ◽  
pp. 218-228
Author(s):  
Bartłomiej Chomiuk ◽  
Janusz Skrzypacz
Keyword(s):  
Numerical Simulations ◽  
Experimental Research ◽  
Liquid Flow ◽  
Centrifugal Pumps ◽  
Pump Unit ◽  
Manufacturing Costs ◽  
Flow Through ◽  
Low Specific Speed ◽  
Specific Speed ◽  
The Impact

AbstractThe article presents the results of numerical analyses and experimental research of the influence of various types of stators on a liquid flow through a centrifugal pump with a hole impeller. It is a continuation of authors research of cooperation pump stators with alternative types of impellers which work in ultra low specific speed. Hole impellers have become a significant alternative to classical ones in a range of extremely low specific speed nq<10. The aim of the research is to verify the quality as well as quantity of computer modeling results, and to estimate accuracy by examining the impact of a grid and a turbulence model with which the numerical simulations reflect the actual flow.Knowledge concerning construction of hydraulic elements of centrifugal pumps working in the range of parameters corresponding specific speed (nq<10) is insufficient. The outlet elements were tested in various configurations of constructional features. The complexity of the construction of the stator can significantly affect the manufacturing costs of pump unit.

scholarly journals Four-quadrant Characterization of Hydrodynamic Phenomena in a Low Specific Speed Centrifugal Pump

2021 ◽  
Vol 25 ◽  
Author(s):  
Hernan Dario Bolaños ◽  
Francisco Botero
Keyword(s):  
Centrifugal Pump ◽  
Classical Method ◽  
Characteristic Curve ◽  
Frequency Domain Analysis ◽  
Rotating Stall ◽  
Low Specific Speed ◽  
Specific Speed ◽  
Four Quadrant

Objective: Identify and characterize subsynchronous hydrodynamics phenomena in a low specific speed centrifugal pump based on its four-quadrant characteristic curve. Materials: A 1.5 HP ITT Goulds pump instrumented with pressure transductors, an accelerometer, a torque sensor and a tachometer. Flow rate measurement was done with an ultrasonic transit time clamp-on flow meter. Methods: Time and frequency domain analysis with phase analysis were used to identify spectral components linked to hydrodynamic phenomena such as rotating stall and surge. Results and discussion: This work approaches an alternative method to calculate the phase angle using pressure signals without filtering. Related with hydrodynamic phenomena, the evidence collected suggests the presence of rotating stall in some operation points of the four-quadrant characteristic curve. Furthermore, in the third quadrant, rotating stall coexist with surge. Conclusions: The instrumentation and methods regarded in this work allow to collect evidence to identify in-phase and out of phase subsynchronous hydrodynamic phenomena. The classic cross-correlation-based method was improved to ease the diagnosis of subsynchronous phenomena by visual inspection. A new quantitative approach was introduced to detect subsynchronous phenomena, based on the Fourier analysis; it was validated with a case study for which the classical method was not suitable.

CFD-Based Hydraulic Design and Manufacturing of a Multistage Low Specific-Speed Diffuser Pump

2019 ◽  
Author(s):  
Martijn van der Schoot ◽  
Kevin Bruurs ◽  
Eric van der Zijden
Keyword(s):  
Manufacturing Process ◽  
Performance Test ◽  
Guide Vane ◽  
Response Surfaces ◽  
Pump Design ◽  
Simulation Based Design ◽  
Final Design ◽  
Low Specific Speed ◽  
Specific Speed ◽  
Mechanical Pump

Abstract A multistage low specific-speed diffuser pump was designed to achieve very good hydraulic performance with a newly designed integrated diffuser, crossover and return guide vane. The diffuser was designed using a continuous crossover design. The design space of this diffuser was limited because of the usage of a mechanical pump design from a similar existing pump. This paper presents the simulation-based design of this new pump and the role that simulation can play in the manufacturing process. A new diffuser has been designed to obtain optimum efficiency and to ensure that the pump will operate most of its time very close its best efficiency point. The new diffuser was designed using an approach where the diffuser vane was stretched to completely cover the area starting just behind the impeller trailing edge towards the eye of the next stage impeller. This means that the diffuser vanes should now convert velocity into pressure, guide the fluid to the next stage impeller eye while reducing the swirl and uniformizing the flow. The shape of the diffuser has been optimized using response surfaces that were created using Computation Fluid Dynamics (CFD). This way, a diffuser with a minimum amount of losses was obtained, due to smooth and gradual area changes of the waterway. The final design incorporating this diffuser was analyzed using steady-state CFD to create the full performance curve. The design was transferred into a real physical product by manufacturing it. The resulting casting of the diffuser component was scanned using a 3D scanner. The 3D model of the scan was used to make a comparison using CFD between the performance of the designed and the manufactured diffuser. This provided understanding in how deviations due to the manufacturing process influence the performance. Finally, the complete pump underwent a performance test and its results closely matched the performance as calculated using CFD.

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