Investigation of Hydraulic Design for High Performance Multi-Stage Pump Using CFD

2009 ◽  
Author(s):  
Takahide Nagahara ◽  
Yasuhiro Inoue
Keyword(s):  
Flow Field ◽  
High Performance ◽  
High Efficiency ◽  
Design Flow ◽  
Parameter Design ◽  
Design Parameters ◽  
Hydraulic Loss ◽  
Highly Efficient ◽  
Multi Stage ◽  
Hydraulic Design

We investigated the hydraulic design and flow field in a multi-stage pump to achieve high efficiency and low cavitation performance using computational fluid dynamics (CFD) and experimental approaches. The subject of the investigation is a four-stage centrifugal pump, which consists of a suction bend, impellers, stators, and a discharge volute. In designing a high performance multi-stage pump, it is important to investigate the interaction of flows between the stator and impeller, which were also investigated individually for minimizing hydraulic loss. The flow field in the suction bend, therefore, was simulated first using conventional CFD based on the Reynolds-Averaged Navier-Stokes (RANS) equations, and the calculated result of the flow field at the outlet of the suction bend was used to design the impeller inlet shape at the design-flow rate. To obtain a high-performance impeller shape, the effect of the meridional configuration of the impeller on hydraulic loss was examined using a parameter design based on conventional CFD results. The meridional shape was composed of several design parameters such as inlet, outlet diameter and so on, and a few parameters, which contribute to reducing hydraulic loss significantly, were extracted using the parameter design. Therefore, we obtained a highly efficient impeller shape by adjusting those important parameters. Finally, to evaluate and confirm the interaction of the flows between the stators and impeller, a numerical calculation of the four-stage pump was carried out using advanced large eddy simulation (LES). As a result, we obtained the predicted flow field in the four-stage pump. There was no significant flow separation at the inlet of each impeller and it was confirmed that the blade design was appropriate. The hydraulic performance of the four-stage pump was also confirmed using a model pump test. The inception of cavitation was observed and the cavitation coefficient estimated using experimental results was in good agreement with the CFD prediction. As a result of this development including the investigation described above, the hydraulic shape of a highly efficient and high-cavitation performing four-stage pump was obtained.

Design of a High-Performance Axial Compressor for Utility Gas Turbine

1992 ◽  
Vol 114 (2) ◽  
pp. 277-286 ◽  
Author(s):  
A. Sehra ◽  
J. Bettner ◽  
A. Cohn
Keyword(s):  
Gas Turbine ◽  
High Performance ◽  
High Efficiency ◽  
Guide Vane ◽  
Design Flow ◽  
Design Parameters ◽  
Design System ◽  
Inlet Guide Vane ◽  
Variable Geometry ◽  
Compressor Design

An aerodynamic design study to configure a high-efficiency industrial-size gas turbine compressor is presented. This study was conducted using an advanced aircraft engine compressor design system. Starting with an initial configuration based on conventional design practice, compressor design parameters were progressively optimized. To improve the efficiency potential of this design further, several advanced design concepts (such as stator ends bends and velocity controlled airfoils) were introduced. The projected poly tropic efficiency of the final advanced concept compressor design having 19 axial stages was estimated at 92.8 percent, which is 2 to 3 percent higher than the current high-efficiency aircraft turbine engine compressors. The influence of variable geometry on the flow and efficiency (at design speed) was also investigated. Operation at 77 percent design flow with inlet guide vanes and front five variable stators is predicted to increase the compressor efficiency by 6 points as compared to conventional designs having only the inlet guide vane as variable geometry.

Design of a High Performance Axial Compressor for Utility Gas Turbine

1991 ◽  
Author(s):  
A. Sehra ◽  
J. Bettner ◽  
A. Cohn
Keyword(s):  
Gas Turbine ◽  
High Performance ◽  
High Efficiency ◽  
Guide Vane ◽  
Design Flow ◽  
Design Parameters ◽  
Design System ◽  
Inlet Guide Vane ◽  
Variable Geometry ◽  
Compressor Design

An aerodynamic design study to configure a high efficiency industrial-size gas turbine compressor is presented. This study was conducted using an advanced aircraft engine compressor design system. Starting with an initial configuration based on conventional design practice, compressor design parameters were progressively optimized. To further improve the efficiency potential of this design, several advanced design concepts (such as stator ends bends and velocity controlled airfoils) were introduced. The projected polytropic efficiency of the final advanced concept compressor design having 19 axial stages was estimated at 92.8 percent, which is 2 to 3 percent higher than the current high efficiency aircraft turbine engine compressors. The influence of variable geometry on the flow and efficiency (at design speed) was also investigated. Operation at 77 percent design flow with inlet guide vanes and front five variable stators is predicted to increase the compressor efficiency by 6 points as compared to conventional designs having only the inlet guide vane as variable geometry.

Dynamic Characteristics of Planetary Gearbox of Shield Tunnelling Machine

2010 ◽  
Vol 139-141 ◽  
pp. 2413-2417
Author(s):  
Zheng Ming Xiao ◽  
Da Tong Qin
Keyword(s):  
High Efficiency ◽  
Critical Issue ◽  
Design Parameters ◽  
Parameter Method ◽  
Subway Tunnel ◽  
Fe Method ◽  
Shield Tunneling ◽  
Planetary Gears ◽  
Planetary Gearbox ◽  
Multi Stage

Shield tunneling machine(STM) is a safety and high-efficiency excavator in the subway tunnel project, but the dynamics of whose multi-stage planetary gearbox is still a critical issue. In this paper, the torsional dynamic model for three-stage planetary gears train(PGT) is developed by lumped parameter method. According to the configuration and design parameters of the planetary gearbox, the natural frequencies are calculated, and the vibration modes are also analyzed. The natural modes can be classified into one of the three categories: rigid-body mode, distinct modes and planet modes. By using finite element(FE) method, the vibration characteristics of gearbox housing are also computed and analyzed for lucubrating vibration transfer and coupling between planetary gears train and housing, which is the important foundation for dynamic optimization of planetary gearbox.

“Fiber-in-tube” hierarchical nanofibers based on defect-rich bimetallic oxide@C bubbles: a high-efficiency and superior performance cathode for hybrid Zn batteries

2020 ◽  
Vol 8 (28) ◽  
pp. 13996-14005 ◽  
Author(s):  
Yang Zhou ◽  
Yu Song ◽  
Sen Zhang ◽  
Chao Deng
Keyword(s):  
High Performance ◽  
High Efficiency ◽  
Superior Performance ◽  
Highly Efficient

“Fiber-in-tube” hierarchical structured nanofibers based on defective bimetallic oxide@C bubbles are a highly efficient and high-performance cathode for flexible hybrid Zn batteries.

Effects of Blade Inlet Width on Performance of Centrifugal Pump as Turbine With Special Impeller Using in Turbine Mode

2016 ◽  
Author(s):  
Tao Wang ◽  
Xiaobing Liu ◽  
Xide Lai ◽  
Qiuqin Gou
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
High Efficiency ◽  
Cost Effective ◽  
Pressure Head ◽  
Design Flow ◽  
Hydraulic Loss ◽  
Obvious Effect ◽  
Velocity Moment ◽  
Turbine Mode

A reverse running centrifugal pump is one of the attractive choices in micro-hydropower development and industrial pressure energy recovery. One of the main problems in utilizing pump as turbine (PAT) is that the performance of PAT is usually not ideal due to the impeller with the routine backward curved blades which do not match well with turbine running condition. A cost effective suitable way for solving this problem is to redesign impeller with forward curved blades from turbine working condition while the other components do not undergo any modifications. Blade inlet width is one of the main factors in impeller design. Therefore, research on the influence of blade inlet width on PAT performance is useful. In this paper, based on the constant velocity moment theory, the velocity moment at impeller inlet is acquired, firstly. Next, a relationship expression between blade inlet angle and the design flow rate is deduced. To perform research on blade inlet width influencing PAT’s performance with special impeller, three impellers which inlet widths are 13 mm, 16 mm and 19 mm, respectively, are designed by using ANSYS Bladegen software. Numerical simulation and analysis of the three PATs are performed using a verified computational fluid dynamics (CFD) technique. Comparison of three PATs’ performance curves obtained by CFD, we can find that the blade inlet width has obvious effect on the performance of PAT. The flow rate, required pressure head, generated shaft power, and efficiency at best efficiency point (BEP) increase with the increase of blade inlet width. The flow rates of three PATs at BEP are about 90 m3/h, 100 m3/h and 105 m3/h, respectively, when impeller inlet width varies from 13 mm to 16 mm and 19 mm. The BEP of three PATs shifts towards higher discharge and its high efficiency range becomes wider with the increase of blade inlet width. At above 100 m3/h discharge, the PAT efficiency increases in accordance with the increase of blade inlet width. And the hydraulic loss and turbulence kinetic energy loss within impeller decrease with the increase of blade inlet width. In order to improve efficiency, it is helpful to choose a relatively larger blade inlet width in the design of special impeller using in turbine mode of PAT.

A Non-Dimensional Quasi-3D Blade Design Approach With Respect to Aerodynamic Criteria

2008 ◽  
Author(s):  
Amit Kumar Dutta ◽  
Peter Michael Flassig ◽  
Dieter Bestle
Keyword(s):  
Design Process ◽  
High Performance ◽  
Thickness Distribution ◽  
Computational Effort ◽  
Design Flow ◽  
Computational Time ◽  
Design Parameters ◽  
Angle Distribution ◽  
Blade Design ◽  
Additional Increase

The competition between aero-engine manufacturers has increased dramatically in the last decades. Saving computational time within the design process, which is equivalent to saving money, is of major importance for the industry. Talking about the aerodynamic compressor blading process, it becomes indispensable to go for new or alternative ways in designing blades in order to fulfill raised performance demands. The focus of this paper, therefore, is to propose a quasi-3D aerodynamic design concept with extended and improved parameterization of the aerofoil in order to support the industrial blading process. A Be´zier-surface is selected to parameterize the non-dimensional camber-line angle distribution along the blade chord from leading to trailing edge over the entire blade height in radial direction. Starting from scratch, the geometric blade build-up is completed by superposing the resulting camber-line with a given thickness distribution. For additional increase of design freedom, Be´zier-curves are used to radially parameterize blade inlet and outlet angles in their dimensionless form. The chosen parameterization of these distributions guarantees smooth blade shapes and geometry distributions with a minimum of design parameters. For optimization purpose it is essential to get performance information on the entire blade, however, with minimal computational effort. Facing this challenge, aerodynamic blade performance is evaluated by a two-dimensional blade-to-blade flow solver for specific sections on different radial blade heights. In order to speed up the blade design process, the flow calculations are realized by a distributed computing concept on a Linux high-performance cluster. All investigations are carried out for highly loaded controlled diffusion blades which are taken from an existing industrial research application. Since selected criteria such as mean loss at design point conditions and working range for off-design flow conditions represent contradicting design goals, the blade design problem is solved by means of a multi-objective problem formulation and a stochastic optimization algorithm. As a result Pareto-optimal trade-off solutions between conflicting design goals are shown where the design engineer can choose from according to his specific preferences.

scholarly journals The Optimal Hydraulic Design of Centrifugal Impeller Using Genetic Algorithm with BVF

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Xin Zhou ◽  
Yongxue Zhang ◽  
Zhongli Ji ◽  
Hucan Hou
Keyword(s):  
Genetic Algorithm ◽  
Design Theory ◽  
Hydraulic Performance ◽  
Design Parameters ◽  
Centrifugal Impeller ◽  
Hydraulic Loss ◽  
Operation Condition ◽  
Pump Impeller ◽  
Hydraulic Design ◽  
Vorticity Flux

Derived from idea of combining the advantages of two-dimensional hydraulic design theory, genetic algorithm, and boundary vorticity flux diagnosis, an optimal hydraulic design method of centrifugal pump impeller was developed. Given design parameters, the desired optimal centrifugal impeller can be obtained after several iterations by this method. Another 5 impellers with the same parameters were also designed by using single arc, double arcs, triple arcs, logarithmic spiral, and linear-variable angle spiral as blade profiles to make comparisons. Using Reynolds averaged N-S equations with a RNGk-εtwo-equation turbulence model and log-law wall function to solve 3D turbulent flow field in the flow channel between blades of 6 designed impellers by CFD code FLUENT, the investigation on velocity distributions, pressure distributions, boundary vorticity flux distributions on blade surfaces, and hydraulic performance of impellers was presented and the comparisons of impellers by different design methods were demonstrated. The results showed that the hydraulic performance of impeller designed by this method is much better than the other 5 impellers under design operation condition with almost the same head, higher efficiency, and lower rotating torque, which implied less hydraulic loss and energy consumption.

Development of a Comprehensive Matlab/Simulink Based Model for High-Efficiency 2nd Generation Photovoltaic (PV) Modules

2020 ◽  
Vol 16 (4) ◽  
pp. 568-577
Author(s):  
Muhammad Naveed Shaikh ◽  
Qayyum Zafar ◽  
Antonis Papadakis
Keyword(s):  
Environmental Conditions ◽  
High Performance ◽  
High Efficiency ◽  
Electrical Performance ◽  
Design Parameters ◽  
Energy Yield ◽  
Pv System ◽  
Matlab Simulink ◽  
2Nd Generation ◽  
Pv Modules

Background: The accurate energy yield prediction of a PV system under various environmental conditions is important for designing a high-performance PV system. Objective: The robust and cost-effective digital simulation studies on PV systems have the advantage in comparison to studies based on measurements because they provide the opportunity for sensitivity analysis on various design parameters of the PV system. Methods: Herein, we present the development and implementation of a generalized photovoltaic computational model using Matlab/Simulink software package. The model is based on the equivalent diode circuit approach. It is designed to simulate two ubiquitous and high performing 2nd generation photovoltaic (PV) modules constructed with Cadmium Telluride (CdTe) and Copper Indium Gallium di-Selenide (CIGS) photoactive thin films, respectively. The values of key input parameters to the simulator, i.e., parallel resistor (Rp) and series resistor (Rs) have been computed by an efficient Newton-Raphson iteration method. Results: The output current-voltage (I-V) and power-voltage (P-V) characteristic curves of the aforementioned PV modules have been simulated by taking two input variables (ambient irradiance and temperature) into consideration. The electrical performance of both PV modules under various environmental conditions have been mathematically investigated by the solution of classical non-linear equations. Conclusion: The developed PV model has been validated with the experimental results obtained from standard PV module datasheets provided by manufacturers. The relative error between the simulated and experimental values of various photovoltaic parameters for CdTe and CIGS PV modules at Standard Test Conditions (STC) has been observed to be below 3%.

scholarly journals Energy Performance Optimization of a House with Grid-Connected Rooftop PV Installation and Air Source Heat Pump

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 740
Author(s):  
George Stamatellos ◽  
Olympia Zogou ◽  
Anastassios Stamatelos
Keyword(s):  
Heat Pump ◽  
Performance Optimization ◽  
High Performance ◽  
Fossil Fuels ◽  
High Efficiency ◽  
Energy Transition ◽  
Building Energy ◽  
Energy Performance ◽  
Design Parameters ◽  
Air Source Heat Pump

The use of air source heat pump systems for space heating and cooling is a convenient retrofitting strategy for reducing building energy costs. This can be combined with the rooftop installation of photovoltaic panels, which can cover, to a significant degree—or even significantly exceed the building’s electricity needs, moving towards the zero energy building concept. Alternatively, increased capacity for rooftop photovoltaic (PV) installation may support the ongoing process of transforming the Greek power system away from the reliance on fossil fuels to potentially become one of the leaders of the energy transition in Europe by 2030. Standard building energy simulation tools allow good assessment of the Heating, Ventilation and Air Conditioning (HVAC) and PV systems’ interactions in transient operation. Further, their use enables the rational sizing and selection of the type of panels type for the rooftop PV installation to maximize the return on investment. The annual performance of a three-zone residential building in Volos, Greece, with an air-to-water heat pump HVAC system and a rooftop PV installation, are simulated in a TRNSYS environment. The simulation results are employed to assess the expected building energy performance with a high performance, inverter driven heat pump with scroll compressor and high efficiency rooftop PV panels. Further, the objective functions are developed for the optimization of the installed PV panels’ area and tilt angle, based on alternative electricity pricing and subsidies. The methodology presented can be adapted to optimize system design parameters for variable electricity tariffs and improve net metering policies.

Investigation of the Flow Field in a Multistage Pump by Using LES

2005 ◽  
Author(s):  
Takahide Nagahara ◽  
Yasuhiro Inoue ◽  
Toshiyuki Sato ◽  
Shinji Sakata ◽  
Kazumi Nishimura ◽  
...  
Keyword(s):  
Flow Field ◽  
Design Tool ◽  
Design Flow ◽  
Navier Stokes ◽  
Scaled Model ◽  
Eddy Simulation ◽  
Hydraulic Design ◽  
Large Eddy ◽  
Multistage Pump ◽  
Effective Design

Unsteady numerical calculation of an entire multistage pump was performed by using a large eddy simulation (LES) at the design flow rate to investigate the flow field in the pump in detail and to evaluate the accuracy of LES by comparing the results with an experimental and a conventional CFD result based on a Reynolds-averaged Navier-Stokes (RANS) equation. We investigated a four-stage centrifugal pump consisting of a suction bend, impellers, vaned diffusers, return channels, and a discharge volute. The interaction between the impeller and the stator was taken into account by using a moving overset grid in LES calculations, and the flow field in the inlet portion of each hydraulic part was investigated using the calculated result. In the experimental investigation, velocity distributions and pressure fluctuation were measured at several points by using a scaled model pump. RANS calculation was performed with respect to a single-stage pump composed of the first-stage component of the four-stage pump. We found that the hydraulic design of the four-stage pump is satisfactory and that LES was a very effective design tool for investigating the flow field in detail including the unsteadiness in the hydraulic passageway of the multistage pump.

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