Pumping Unit Power-Density Improvement by Application of Counter-Rotating Impellers Design

2016 ◽  
Vol 138 (11) ◽  
Author(s):  
Stefano Tosin ◽  
Jens Friedrichs ◽  
Andreas Dreiss
Keyword(s):  
Power Density ◽  
Design Method ◽  
Design Tool ◽  
Single Stage ◽  
Production Costs ◽  
Energy Concentration ◽  
Experimental Investigations ◽  
Speed Ratio ◽  
Numerical Predictions ◽  
House Design

In many industrial areas, downsizing the pumping system is a decisive aim of the designers. The reasons could be multiple means; in a single-stage pump, increasing the power density of the pump means actually reducing the production costs. The main goal of this study was the comparison in terms of power density of a conventionally designed single-stage pump with a novel design concept based on the counter-rotating (CR) principle. In order to simplify the experimental investigations for the present study, the volute geometry was fixed instead of reducing the pump outflow diameters for a fixed design point. The energy concentration was then increased by raising the developed hydraulic power within the same envelope. The design of the impellers was carried out with an in-house design tool, based on inverse design method. Numerical results highlight the advantageousness of the new layout, in terms of power concentration, compared to the conventional impeller. Numerical predictions are also in significant agreement with the experimental investigation results, obtained in a specifically developed CR motors test rig. The experimental optimization of the rotational speed ratio of the CR impellers has shown the possibility to further increase the head in off-design condition and thereby the pump power density.

scholarly journals Experimental Validation of the Aerodynamic Performance of an Innovative Counter-Rotating Centrifugal Compressor

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2582
Author(s):  
Cheikh Brahim ABED ◽  
Sofiane KHELLADI ◽  
Michael DELIGANT ◽  
Abdellatif EL EL MARJANI ◽  
Moisés SOLIS ◽  
...  
Keyword(s):  
Experimental Data ◽  
Centrifugal Compressor ◽  
Degrees Of Freedom ◽  
Experimental Validation ◽  
Design Method ◽  
Pressure Rise ◽  
Design Tool ◽  
Centrifugal Impeller ◽  
Speed Ratio ◽  
And Control

Turbomachinery with double counter-rotating impellers offers more degrees of freedom in the choice of design and control parameters compared to conventional machines. For these innovative machines, the literature review shows that more publications concerning axial type turbomachines are available than centrifugal ones. This work deals with a design and experimental performance analysis, applied to two counter-rotating impellers of a centrifugal compressor “CRCC”. CRCC was designed with a specifically developed tool based on mean-line approach coupled with optimization algorithms and a stream-curvature through-flow method to satisfy the design criteria. This paper presents an experimental validation of the CRCC design tool and its performances against the baseline “SR”, composed of one centrifugal impeller and a volute for which experimental data are available. CRCC numeric simulations are also validated by experimental data. For a fair comparison between CRCC and SR, the same volute is used for both configurations. The CRCC studied here includes a first conventional impeller with an axial inlet and a radial outlet, while the second impeller is parametrically designed and can be considered a rotating bladed diffuser with a radial inlet and outlet. The obtained results show that CRCC can deliver a pressure rise increase of two compared to SR, along with an increase of isentropic efficiency and also validate the design method of this novel layout. The experimental results also show that the speed ratio of CRCC has a positive effect on the surge and shock margin.

scholarly journals Co-Design of CVT-Based Electric Vehicles

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1825
Author(s):  
Caiyang Wei ◽  
Theo Hofman ◽  
Esin Ilhan Caarls
Keyword(s):  
Cooling System ◽  
Design Method ◽  
Low Cost ◽  
Cost Effective ◽  
Speed Ratio ◽  
Air Flow Rate ◽  
Cost Of Ownership ◽  
Variable Transmission ◽  
Primary Focus ◽  
Design Freedom

For an electric vehicle (EV) with a continuously variable transmission (CVT), a novel convex programming (CP)-based co-design method is proposed to minimize the total-cost-of-ownership (TCO). The integration of the electric machine (EM) and the CVT is the primary focus. The optimized system with co-design reduces the TCO by around 5.9% compared to a non-optimized CVT-based EV (based on off-the-shelf components) and by around 2% compared to the EV equipped with a single-speed transmission (SST). By taking advantage of the control and design freedom provided by the CVT, the optimal CVT, EM and battery sizes are found to reduce the system cost. It simultaneously finds the optimal CVT speed ratio and air-flow rate of the cooling system reducing the energy consumption. The strength of co-design is highlighted by comparing to a sequential design, and insights into the design of a low-power EV that is energy-efficient and cost-effective for urban driving are provided. A highly integrated EM-CVT system, which is efficient, low-cost and lightweight, can be expected for future EV applications.

Influence of a Honeycomb Facing on the Flow Through a Stepped Labyrinth Seal

2000 ◽  
Vol 124 (1) ◽  
pp. 140-146 ◽  
Author(s):  
V. Schramm ◽  
K. Willenborg ◽  
S. Kim ◽  
S. Wittig
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Theoretical Work ◽  
Labyrinth Seal ◽  
Honeycomb Structure ◽  
Experimental Investigations ◽  
Labyrinth Seals ◽  
Numerical Predictions ◽  
Flow Through ◽  
Aero Engines

This paper reports numerical predictions and measurements of the flow field in a stepped labyrinth seal. The theoretical work and the experimental investigations were successfully combined to gain a comprehensive understanding of the flow patterns existing in such elements. In order to identify the influence of the honeycomb structure, a smooth stator as well as a seal configuration with a honeycomb facing mounted on the stator wall were investigated. The seal geometry is representative of typical three-step labyrinth seals of modern aero engines. The flow field was predicted using a commercial finite volume code with the standard k-ε turbulence model. The computational grid includes the basic seal geometry as well as the three-dimensional honeycomb structures.

HyperGear: An Object Oriented Design Program for Single Stage Gear Box Design

1991 ◽  
Author(s):  
Gary A. Gabriele ◽  
Agustî Maria I. Serrano
Keyword(s):  
Computer Aided Design ◽  
Object Oriented ◽  
Design Tool ◽  
Single Stage ◽  
Design Tools ◽  
Object Oriented Design ◽  
Computer Aided ◽  
Gear Box ◽  
Aided Design ◽  
Object Oriented Languages

Abstract The need for superior design tools has lead to the development of better and more complex computer aided design programs. Two of the more important new developments in application tools being investigation are Object Oriented Languages, and HyperMedia. Object Oriented Languages allow the development of CAD tools where the parts being designed and the design procedures specified are conceptualized as objects. This allows for the development of design aids that are non-procedural and more readily manipulated by the user trying to accomplish a design task. HyperMedia allows for the easy inclusion of many different types of data, such as design charts and graphs, into the tool that are normally difficult to include in design tools programmed with more conventional programming languages. This paper explores the development of a computer aided design tool for the design of a single stage gear box using the development HyperCard® environment and the HyperTalk® programming language. The resulting program provides a user friendly interface, the ability to handle several kinds of design information including graphic and textual, and a non-procedural design tool to help the user design simple, one stage gear boxes. Help facilities in the program make it suitable for undergraduate instruction in a machine elements design course.

Analysis and Design of a Single‐Stage Isolated DC / AC Converter for a High‐Power‐Density Onboard AC Inverter

2021 ◽  
Author(s):  
Kenichi Itoh ◽  
Rene Barrera‐Cardenas ◽  
Masanori Ishigaki ◽  
Takahide Sugiyama ◽  
Takanori Isobe ◽  
...  
Keyword(s):  
Power Density ◽  
High Power ◽  
Single Stage ◽  
High Power Density ◽  
Analysis And Design

Numerical and Experimental Investigations on Preload Effects in Air Foil Journal Bearings

2017 ◽  
Author(s):  
Marcel Mahner ◽  
Pu Li ◽  
Andreas Lehn ◽  
Bernhard Schweizer
Keyword(s):  
Reynolds Equation ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Compressible Fluids ◽  
Experimental Investigations ◽  
Hysteresis Curves ◽  
Numerical Predictions ◽  
Bearing Stiffness ◽  
Gasdynamic Model ◽  
Good Agreement

A detailed elasto-gasdynamic model of a preloaded three-pad air foil journal bearing is presented. Bump and top foil deflections are herein calculated with a nonlinear beamshell theory according to Reissner. The 2D pressure distribution in each bearing pad is described by the Reynolds equation for compressible fluids. With this model, the influence of the assembly preload on the static bearing hysteresis as well as on the aerodynamic bearing performance is investigated. For the purpose of model validation, the predicted hysteresis curves are compared with measured curves. The numerically predicted and the measured hysteresis curves show a good agreement. The numerical predictions exhibit that the assembly preload increases the bearing stiffness (in particular for moderate shaft displacements) and the bearing damping.

scholarly journals The House Reformed: A Reaction to Suburban Monotony

2021 ◽  
Author(s):  
◽  
Florence Mangan
Keyword(s):  
Design Method ◽  
Well Being ◽  
Mass Scale ◽  
Life Styles ◽  
Hands On ◽  
Final Design ◽  
Manual Methods ◽  
The Aesthetic ◽  
House Design ◽  
Made In

<p>Joyless rows of monotonous houses are be- ginning to define the suburban typology of tomorrow. Quality and innovation is being compromised for speed and quantity and there is a distinct lack of consideration for the home’s potential to enrich and influence the life-styles and well-being of its occupants.  This thesis is a reaction to the researcher’s dis- satisfaction with New Zealand’s suburban typology and seeks to identify and demonstrate an alternative design approach. The research- er considers that a house should enable its occupants to flourish by instigating moments of joy and surprise whilst maximising economy of space.  The thesis uses an investigative research method of five different design tests. Each test reveals strategies to aid the approach of designing the suburban typology, focusing on maximising joy, surprise and economy of space.  Both digital and manual methods are used, revealing their respective strengths and flaws. The Digital method used in the Data House and Rigid x Fluid house tests lacked the ability to apply tangible aesthetic qualities to a de- sign. The manual hands on method of used in the Patchwork House and House Reformed tests was hugely beneficial for the aesthetic qualities of design, however it lacked the rigor and capacity to apply individuality on a mass scale.  Discoveries made in the thesis investigations are collated in a final design outcome, the House Reformed. This house design demonstrates a compilation of the successful strategies identified in the research and reveals the benefits of approaching home design with qualities of joy, surprise and economy of space. The most successful strategies used to achieve these aims were establishing a great- er connection with the outdoors, providing flexible spaces through the use of innovative partitions and furniture and injecting unexpected aesthetic moments through the use of interesting texture and colour.  Overall the research reveals a successful de- sign outcome and provides interesting in- sights into design method. It explores worth- while questions and issues related to the lived domestic experience such as the lack of joy, surprise and economy of space in suburban housing and demonstrates the importance of designing with such qualities.</p>

scholarly journals Hardware Implementation of FTC of Induction Machine on FPGA

2017 ◽  
Vol 20 (2) ◽  
pp. 76
Author(s):  
S. Boukadida ◽  
S. Gdaim ◽  
A. Mtibaa
Keyword(s):  
Digital Signal Processor ◽  
Fault Tolerant ◽  
Design Method ◽  
Direct Torque Control ◽  
Induction Machine ◽  
Digital Signal ◽  
Design Tool ◽  
Torque Control ◽  
Algorithm Efficiency ◽  
Comparison Results

In this paper, a new design method of Direct Torque Control using Space Vector Modulation (DTC-SVM) of an Induction Machine (IM), which is based on Fault Tolerant Control (FTC) is proposed. Due to its complexity, the FTC implemented on a microcontroller and a Digital Signal Processor (DSP) is characterized by a calculating delay. To solve this problem, an alternative digital solution is used, based on the Field Programmable Gate Array (FPGA), which is characterized by a fast processing speed. However, as an FPGAs increase in size, there is a need for improved productivity, and this includes new design flows and tools. Xilinx System Generator (XSG) is a high-level block-based design tool that offers bit and cycle accurate simulation. This tool can automatically generate the Very High-Density Logic (VHDL) code without resorting to a tough programming, without being obliged to do approximations and more we can visualize the behavior of the machine before implementation which is very important for not damage our machine. Simulation and experimental results using Hardware In the Loop (HIL) of the FTC based DTC-SVM is compared with those of the conventional DTC. The comparison results illustrate the reduction in the torque and stator flux ripples. Our purpose is to reveal our algorithm efficiency and to show the Xilinx Virtex V FPGA performances in terms of execution time. 

Numerical Predictions and Verifications for Hydrodynamic Performance of Bidirectional Tidal Stream Turbine

2012 ◽  
Vol 229-231 ◽  
pp. 2478-2480
Author(s):  
Bin Guo ◽  
Da Zheng Wang ◽  
Jun Wei Zhou
Keyword(s):  
Hydrodynamic Performance ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Numerical Predictions ◽  
Ansys Cfx ◽  
Tidal Stream ◽  
Cfd Method ◽  
Tidal Stream Turbine ◽  
Bem Theory ◽  
Blade Element

In this paper, the tidal stream turbine blade is designed by using blade element momentum (BEM) theory. The bidirectional airfoil is created derived from NACA airfoil. Ansys-CFX is used to predict the hydrodynamic performance of this bidirectional airfoil, and it turns out that the bidirectional airfoil works well at both of the tidal current directions. A test turbine named rotor 2 is used, and a comparison is made between experimental results of the test turbine and numerical prediction results to prove the correctness of the numerical method. The power coefficient of bidirectional tidal stream turbine obtained by CFD method is 39.36% at the design tip speed ratio.

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