scholarly journals Design Options to Improve the Dynamic Behavior and the Control of Small H-Darrieus VAWTs

2021 ◽  
Vol 11 (19) ◽  
pp. 9222
Author(s):  
Lorenzo Battisti
Keyword(s):  
Built Environment ◽  
Urban Environment ◽  
Wind Turbines ◽  
Rational Design ◽  
Design Procedure ◽  
Design Parameters ◽  
Site Characteristics ◽  
Acceleration And Deceleration ◽  
And Performance ◽  
Wind Resource

H-VAWTs or straight blades VAWTs are the most common turbine architecture employed for small VAWTs. The manufacture of straight, constant chord blades, coupled with the transport advantages, make this choice technologically simpler, compared to curved (eggbeater) type or curved-bent (Gorlov) type, allowing a large selection of materials, and design solutions. Recently, the strategies to accomplish the task of zero-emission buildings identified wind energy exploitation in the urban environment as one of the most promising. Micro and mini wind turbines installed on buildings (BAWT—building-augmented wind turbines) are considered the candidate technology after that of photovoltaic panels; under certain conditions, these technologies can be combined to obtain the maximum natural resources exploitation in the urban environment. VAWT, compared to HAWT, would ideally perform better in the fast-changing, turbulent winds, typical of the built environment. Additionally, its 3D shape favors a better architectonic integration with the volumes of the building. Nevertheless, despite these claimed advantages, this architecture did still not come to the expected fruition and experience, which revealed that the stochastic nature of the wind resource in the built environment determines a quite challenging context, reflecting not only the structural endurance, but also the operations and the annual energy production. These site characteristics stress the detrimental effect of the high polar inertia of this architecture hampering, be it a reduction in the acceleration and deceleration capability of the rotor, the required adaptation of the rotational speed to the varying wind conditions, or compromising any form of robust control. This leads to poor aerodynamic performance and potential structural damages. This paper contributes to mitigating the issue of the high rotor polar inertia of the H-VAWT without affecting other essential design requirements (strength, performances, needs of smooth control). The work identifies the design parameters governing the rotor acceleration and deceleration and develops a rational design procedure aimed at improving the H-VAWT control and performance.

scholarly journals Numerical verification of variable friction cladding connection for multihazard mitigation

2020 ◽  
pp. 107754632092393
Author(s):  
Yongqiang Gong ◽  
Liang Cao ◽  
Simon Laflamme ◽  
James Ricles ◽  
Spencer Quiel ◽  
...  
Keyword(s):  
Sliding Friction ◽  
Design Procedure ◽  
Design Parameters ◽  
Numerical Verification ◽  
Structural System ◽  
Passive Energy Dissipation ◽  
Variable Friction ◽  
Friction Cladding ◽  
And Performance ◽  
Selection Of

The motion of cladding systems can be leveraged to mitigate natural and man-made hazards. The literature counts various examples of connections enhanced with passive energy dissipation capabilities at connections. However, because such devices are passive, their mitigation performance is typically limited to specific excitations. The authors have recently proposed a novel variable friction cladding connection capable of mitigating hazards semi-actively. The variable friction cladding connection is engineered to transfer lateral forces from the cladding element to the structural system. Its variation in friction force is generated by a toggle-actuated variable normal force applied onto sliding friction plates. In this study, a multiobjective motion-based design methodology integrating results from the previous work is proposed to leverage the variable friction cladding connection for nonsimultaneous wind, seismic, and blast hazard mitigation. The procedure starts with the quantification of each hazard and performance objectives. It is followed by the selection of dynamic parameters enabling prescribed performance under wind and seismic loads, after which an impact rubber bumper is designed to satisfy motion requirements under blast. Last, the peak building responses are computed and iterations conducted on the design parameters on the satisfaction of the motion objectives. The motion-based design procedure is verified through numerical simulations on two example buildings subjected to the three nonsimultaneous hazards. The performance of the variable friction cladding connection is also assessed and compared against different control cases. Results show that the motion-based design procedure yields a conservative design approach in meeting all of the motion requirements and that the variable friction cladding connection performs significantly well at mitigating vibrations.

Assessing Wind Resource Potential in the Built Environment

2011 ◽  
Author(s):  
Susan W. Stewart ◽  
Sue Ellen Haupt ◽  
Julia A. Cole
Keyword(s):  
Built Environment ◽  
Power Density ◽  
Wind Turbines ◽  
Field Measurements ◽  
Detached Eddy Simulation ◽  
Existing Structures ◽  
Eddy Simulation ◽  
Power Maps ◽  
Wind Resource ◽  
Over The Top

This study addresses the issue of siting wind turbines on existing structures in the built environment for optimal performance. Annually averaged wind power maps were produced over the surface of two different building types using a Detached Eddy Simulation (DES) model in order to assess the feasibility of building integrated wind under various wind resource conditions. The modeling approach was first applied to a cubical geometry for which validation of the CFD results was possible with existing field measurements. A pitched roof building was also modeled to study the power density over top of typical residential shaped structures. The average annual power density for twenty-seven locations over the top of the modeled structures was analyzed under varying wind direction distributions (wind roses). The overall results of this study have the potential to inform the wind energy and built environment communities on best practices for siting wind turbines on or near buildings.

scholarly journals Design Specifications and Performance analysis of Single and Two Stage HB LLC Converters

2019 ◽  
Vol 9 (1S) ◽  
pp. 192-196
Keyword(s):  
Performance Analysis ◽  
Software Package ◽  
Design Procedure ◽  
Input Voltage ◽  
Design Parameters ◽  
Basic Operation ◽  
Two Stage ◽  
Design Specifications ◽  
Converter Topologies ◽  
And Performance

In this paper a Single stage and Two stage Half Bridge LLC (HB LLC) converter topologies for DC/DC applications with low input voltage. The basic operation and design procedure for LLC converter is illustrated. Simulation of the proposed converter is done using the design parameters and the results are discussed and then analysis is done to know its performance. The efficiency of the converters is analyzed by MATLAB Software Package.

scholarly journals Fabrication and Performance Evaluation of Savonious Vertical Axis Wind Turbine for Uncertain Speed Regions

2017 ◽  
Vol 13 (2) ◽  
Keyword(s):  
Performance Evaluation ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Urban Areas ◽  
Vertical Axis ◽  
Design Parameters ◽  
Vertical Axis Wind Turbine ◽  
Horizontal Axis Wind Turbine ◽  
Vertical Axis Wind Turbines ◽  
And Performance

The consumption of electricity in urban as well as rural is increasing every day and became an essential commodity for household and industrial purposes. Unfortunately the availability of electrical energy in India is not sufficient to the required demand and it is essential to discover and generate energy from non-conventional sources with cheap cost. On the same time it is necessary to reduce the consumption of conventional sources and to save fuel. Among all the renewable resources, wind is one of the best resources available all the time at free of cost. Especially vertical axis wind turbines (VAWT) are self-starting, omni directional. They require no yaw mechanism to continuously orient towards the wind direction and provide a more reliable energy conversion technology, as compared to horizontal axis wind turbine. Particularly savonius vertical axis wind turbines (SVAWT) are suitable and practically possible at low or uncertain wind speed regimes. They can be fitted on rooftops and also suitable for the urban areas where electricity is not available properly. This project deals with the fabrication and performance evaluation of savonius vertical axis wind turbine using two blade rotor. The amount of power developed by the wind turbine is calculated under theoretical and practical conditions and aerodynamics coefficients are also estimated. And various design parameters of savonious rotor are identified and determined.

Gas Dynamic Designs of Centrifugal Compressors for Gas Industry

2015 ◽  
Author(s):  
Y. Galerkin ◽  
A. Rekstin ◽  
K. Soldatova ◽  
A. Drozdov
Keyword(s):  
High Efficiency ◽  
Pressure Ratio ◽  
Design Procedure ◽  
Flow Coefficient ◽  
Design Parameters ◽  
Centrifugal Compressors ◽  
Gas Industry ◽  
Design Point ◽  
Optimal Values ◽  
And Performance

Centrifugal compressors for gas industry consume huge amount of energy. As a rule, they are single-shaft, with two or more stages and with comparatively low pressure ratio. Compressors operate at low Mach numbers and high Reynolds numbers. Two design parameters influence mostly stage performances. Stage flow coefficient optimal values lie in range 0.060–0.11. Chosen number of stages establishes value of this coefficient if speed of a rotor rotation is fixed. Design loading factor optimal values are 0.42–0.52. It corresponds to high efficiency, shifts a surge limit far from a design point and makes power maximal in a design point. Some considerations about impeller and diffuser types are presented. Design procedure consists on application of the Universal modeling programs for main dimensions optimization and performance calculations. Q3D non-viscid velocity diagrams are analyzed for optimization of blade configuration. Samples of design are presented, 32 MW single-stage pipeline compressor stage with record efficiency included.

Design and Performance of Vaneless Volutes for Radial Inflow Turbines: Part 2: Experimental Investigation of the Mean Line Performance—Assessment of Empirical Design Parameters

1994 ◽  
Vol 208 (3) ◽  
pp. 213-224 ◽  
Author(s):  
A Whitfield ◽  
S A MacGregor ◽  
A B Mohd Noor
Keyword(s):  
Experimental Investigation ◽  
Static Pressure ◽  
Swirling Flow ◽  
Design Procedure ◽  
Design Parameters ◽  
Flow Angle ◽  
One Dimensional ◽  
Specific Objective ◽  
The Mean ◽  
And Performance

The non-dimensional design procedure described in Part 1 assumed a one-dimensional compressible flow and as such relied on the empirical specification of the dissipation of angular momentum, the dissipation of energy and the deviation of the swirling flow from that of a free vortex. This was based largely on data available in the published literature. In order to develop and substantiate the empirical procedures further an experimental study was carried out in parallel with the development of the design procedure. The experimental investigation described here had the specific objective of assessing and developing appropriate empirical models and coefficients for application to the design procedure. The study concentrated on the application of a five-hole probe located in the centre of the volute passage and at a series of azimuth angles around the discharge. The probe provided stagnation and static pressure measurements, from which the gas velocity was derived, together with the flow angle. When taking measurements at the volute discharge a stationary dummy rotor was used to carry the five-hole probe.

scholarly journals DESIGN PROCEDURE AND OPTIMIZATION OF STEERING SYSTEM FOR FORMULA STUDENT CAR.

2021 ◽  
Vol 10 (2) ◽  
pp. 82-102
Keyword(s):  
Design Procedure ◽  
Steering System ◽  
Design Parameters ◽  
Steering Wheel ◽  
Formula Sae ◽  
The Road ◽  
Manufacturing Assembly ◽  
And Performance ◽  
Steering Effort ◽  
Clear Idea

Steering system is one of the major part of any Automotive design. It is responsible for transferring drivers input to the wheels and gives feedback from road to driver. To design a proper steering system for a formula SAE vehicle, several design parameters needed to be determined. The most important design intent for this system was to provide the driver with a system that did not require excessive steering input force or excessive steering wheel rotation, proper wheel feedback, and adequate wheel steering angle to allow the driver to navigate the tightest corners on the autocross course. This report gives clear idea about how the steering geometry has to be decided for formula student car by using CAD Software Solidworks, and how to select from different possible alternatives. Also, designing of steering components like rack and pinion, shafts and Steering wheel is explained in the report. The overall report can be divided into two objectives. The first is to design the proper steering geometry for the car. The second objective is to design the steering system components, so that the steering effort decreases without compensating the feedback which is obtained from the road. Designing and optimizing of steering system and its components is done considering the rules provided by Formula Bharat 2020, ergonomics, drivers safety, Components Manufacturing, Assembly and performance. The CAD file is entirely developed in Solidworks 2018-19. Static force analysis on components is also performed in Solidworks 2018-19.

scholarly journals Towards the engineering of in vitro systems

2009 ◽  
Vol 6 (suppl_4) ◽  
Author(s):  
Christoph Hold ◽  
Sven Panke
Keyword(s):  
Rational Design ◽  
Enzymatic Reaction ◽  
Design Procedure ◽  
Reaction Network ◽  
Living Cells ◽  
Living Systems ◽  
Design Parameters ◽  
In Vitro Systems ◽  
Time Invariant

Synthetic biology aims at rationally implementing biological systems from scratch. Given the complexity of living systems and our current lack of understanding of many aspects of living cells, this is a major undertaking. The design of in vitro systems can be considerably easier, because they can consist of fewer constituents, are quasi time invariant, their parameter space can be better accessed and they can be much more easily perturbed and then analysed chemically and mathematically. However, even for simplified in vitro systems, following a comprehensively rational design procedure is still difficult. When looking at a comparatively simple system, such as a medium-sized enzymatic reaction network as it is represented by glycolysis, major issues such as a lack of comprehensive enzyme kinetics and of suitable knowledge on crucial design parameters remain. Nevertheless, in vitro systems are very suitable to overcome these obstacles and therefore well placed to act as a stepping stone to engineering living systems.

scholarly journals A modular design method based on TRIZ and AD and its application to cutter changing robot

2021 ◽  
Vol 13 (7) ◽  
pp. 168781402110343
Author(s):  
Mei Yang ◽  
Yimin Xia ◽  
Lianhui Jia ◽  
Dujuan Wang ◽  
Zhiyong Ji
Keyword(s):  
Modular Design ◽  
Design Method ◽  
Idea Generation ◽  
Design Parameters ◽  
Problem Analysis ◽  
Concept Design ◽  
Functional Requirements ◽  
Shield Tunneling ◽  
Structural Hierarchy ◽  
And Performance

Modular design, Axiomatic design (AD) and Theory of inventive problem solving (TRIZ) have been increasingly popularized in concept design of modern mechanical product. Each method has their own advantages and drawbacks. The benefit of modular design is reducing the product design period, and AD has the capability of problem analysis, while TRIZ’s expertise is innovative idea generation. According to the complementarity of these three approaches, an innovative and systematic methodology is proposed to design big complex mechanical system. Firstly, the module partition is executed based on scenario decomposition. Then, the behavior attributes of modules are listed to find the design contradiction, including motion form, spatial constraints, and performance requirements. TRIZ tools are employed to deal with the contradictions between behavior attributes. The decomposition and mapping of functional requirements and design parameters are carried out to construct the structural hierarchy of each module. Then, modules are integrated considering the connections between each other. Finally, the operation steps in application scenario are designed in temporal and spatial dimensions. Design of cutter changing robot for shield tunneling machine is taken as an example to validate the feasibility and effectiveness of the proposed method.

scholarly journals A Two-Round Optimization Design Method for Aerostatic Spindles Considering the Fluid–Structure Interaction Effect

2021 ◽  
Vol 11 (7) ◽  
pp. 3017
Author(s):  
Qiang Gao ◽  
Siyu Gao ◽  
Lihua Lu ◽  
Min Zhu ◽  
Feihu Zhang
Keyword(s):  
Optimal Design ◽  
Optimization Design ◽  
Design Method ◽  
Fluid Structure Interaction ◽  
Design Procedure ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Aerostatic Spindle

The fluid–structure interaction (FSI) effect has a significant impact on the static and dynamic performance of aerostatic spindles, which should be fully considered when developing a new product. To enhance the overall performance of aerostatic spindles, a two-round optimization design method for aerostatic spindles considering the FSI effect is proposed in this article. An aerostatic spindle is optimized to elaborate the design procedure of the proposed method. In the first-round design, the geometrical parameters of the aerostatic bearing were optimized to improve its stiffness. Then, the key structural dimension of the aerostatic spindle is optimized in the second-round design to improve the natural frequency of the spindle. Finally, optimal design parameters are acquired and experimentally verified. This research guides the optimal design of aerostatic spindles considering the FSI effect.

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