scholarly journals COUNTER-ROTATING DUAL ROTOR WIND TURBINE LAYOUT OPTIMISATION

2021 ◽  
Vol 61 (2) ◽  
pp. 342-349
Author(s):  
Csaba Hetyei ◽  
Ferenc Szlivka
Keyword(s):  
Fluid Dynamics ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Theoretical Basis ◽  
Energy Demand ◽  
Smart Cities ◽  
Maximum Efficiency ◽  
General Energy ◽  
Turbine Design ◽  
Day By Day

General energy demand is continuously increasing, thus the energy generating assets need to be optimised for higher efficiency. Wind turbines are no exception. Their maximum efficiency can be determined on a theoretical basis. The limit is approached by researches day by day, utilizing the latest developments in airfoil design, blade structure and new and improved ideas in conventional and unconventional wind turbine layouts. In this paper, we are reviewing the conventional and unconventional wind turbines and their place in smart cities. Then, an unconventional wind turbine design, the CO-DRWT (counter-rotating dual rotor wind turbine) is analysed with a CFD (computational fluid dynamics) code, varying the axial and radial distances between the two turbines. After the simulations, the power coefficients for the different turbine configurations is calculated. At the end of this paper, the simulations results are summarized and consequences are drawn for the CO-DRWT layouts.

SHAPING OF AN AUTONOMOUS POWER SYSTEM FOR GUARANTEED POWER SUPPLY WITH THE PREDOMINANCE WIND ENERGY

2018 ◽  
pp. 28-50
Author(s):  
S. G. Ignatiev ◽  
S. V. Kiseleva
Keyword(s):  
Energy Storage ◽  
Wind Speed ◽  
Wind Energy ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Energy Demand ◽  
Diesel Generator ◽  
Average Wind Speed ◽  
Wind Speeds ◽  
Average Wind

Optimization of the autonomous wind-diesel plants composition and of their power for guaranteed energy supply, despite the long history of research, the diversity of approaches and methods, is an urgent problem. In this paper, a detailed analysis of the wind energy characteristics is proposed to shape an autonomous power system for a guaranteed power supply with predominance wind energy. The analysis was carried out on the basis of wind speed measurements in the south of the European part of Russia during 8 months at different heights with a discreteness of 10 minutes. As a result, we have obtained a sequence of average daily wind speeds and the sequences constructed by arbitrary variations in the distribution of average daily wind speeds in this interval. These sequences have been used to calculate energy balances in systems (wind turbines + diesel generator + consumer with constant and limited daily energy demand) and (wind turbines + diesel generator + consumer with constant and limited daily energy demand + energy storage). In order to maximize the use of wind energy, the wind turbine integrally for the period in question is assumed to produce the required amount of energy. For the generality of consideration, we have introduced the relative values of the required energy, relative energy produced by the wind turbine and the diesel generator and relative storage capacity by normalizing them to the swept area of the wind wheel. The paper shows the effect of the average wind speed over the period on the energy characteristics of the system (wind turbine + diesel generator + consumer). It was found that the wind turbine energy produced, wind turbine energy used by the consumer, fuel consumption, and fuel economy depend (close to cubic dependence) upon the specified average wind speed. It was found that, for the same system with a limited amount of required energy and high average wind speed over the period, the wind turbines with lower generator power and smaller wind wheel radius use wind energy more efficiently than the wind turbines with higher generator power and larger wind wheel radius at less average wind speed. For the system (wind turbine + diesel generator + energy storage + consumer) with increasing average speed for a given amount of energy required, which in general is covered by the energy production of wind turbines for the period, the maximum size capacity of the storage device decreases. With decreasing the energy storage capacity, the influence of the random nature of the change in wind speed decreases, and at some values of the relative capacity, it can be neglected.

scholarly journals Design and Analysis of a Wind Turbine Blade with Dimples to Enhance the Efficiency through CFD with ANSYS R16.0

2018 ◽  
Vol 207 ◽  
pp. 02004
Author(s):  
M. Rajaram Narayanan ◽  
S. Nallusamy ◽  
M. Ragesh Sathiyan
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Turbine Blades ◽  
Electrical Energy ◽  
Optimum Combination ◽  
Surface Topology ◽  
Wind Turbine Blades ◽  
Lift And Drag

In the global scenario, wind turbines and their aerodynamics are always subjected to constant research for increasing their efficiency which converts the abundant wind energy into usable electrical energy. In this research, an attempt is made to increase the efficiency through the changes in surface topology of wind turbines through computational fluid dynamics. Dimples on the other hand are very efficient in reducing air drag as is it evident from the reduction of drag and increase in lift in golf balls. The predominant factors influencing the efficiency of the wind turbines are lift and drag which are to be maximized and minimized respectively. In this research, surface of turbine blades are integrated with dimples of various sizes and arrangements and are analyzed using computational fluid dynamics to obtain an optimum combination. The analysis result shows that there is an increase in power with about 15% increase in efficiency. Hence, integration of dimples on the surface of wind turbine blades has helped in increasing the overall efficiency of the wind turbine.

scholarly journals Computational performance analysis of an airborne rotor-type electricity generator wind turbine

2019 ◽  
Vol 128 ◽  
pp. 09007
Author(s):  
Doğan Günes ◽  
Ergin Kükrer ◽  
Tolga Aydoğdu
Keyword(s):  
Fluid Dynamics ◽  
Wind Turbine ◽  
Electrical Energy ◽  
Dynamics Analysis ◽  
Innovative Design ◽  
Computational Performance ◽  
Computational Fluid Dynamics Analysis ◽  
Turbine Design ◽  
Design Proposal ◽  
Rotor Type

This paper presents an analysis of the possible performance of a proposed airborne rotor type electricity generator wind turbine design. The innovative design proposal by inventor is based on the rotation of the airborne structure with blades attached to the airborne zeppelin and thus it is called an airborne rotor generator. In this paper computational fluid dynamics analysis of a model close to the proposed design is carried out and the results are presented. The proposed design examples are set to produce 10-100KW. The electrical energy generated through two symmetrically placed alternators at both ends of the zeppelin is transferred to the ground-based system through the tethered cords used to also stabilize the system. Thus, an airborne rotor generator is formed.

scholarly journals THE PATH FROM FUNCTIONAL TO DETAILED DESIGN OF A CONING ROTOR WIND TURBINE CONCEPT

2011 ◽  
Author(s):  
Curran A. Crawford
Keyword(s):  
Wind Energy ◽  
Wind Turbine ◽  
Detailed Analysis ◽  
Theoretical Basis ◽  
Design Theory ◽  
Functional Design ◽  
Detailed Design ◽  
Definition Of ◽  
The Cost ◽  
Turbine Design

This paper provides a brief overview of functional design theory, which is then used to examine choices in wind turbine design. Definition of function is used to examine fundamental design choices in engineering a machine to capture energy from the wind. Specifically, rationalization is presented for a coning rotor wind turbine concept, potentially able to greatly reduce the cost of wind energy. The work presented here has provided a theoretical basis in design theory to motivate the development of specialized analysis tools and more detailed analysis of the concept.

Investigation of Self-Starting Capability of Vertical Axis Wind Turbines Using a Computational Fluid Dynamics Approach

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Alexandrina Untaroiu ◽  
Houston G. Wood ◽  
Paul E. Allaire ◽  
Robert J. Ribando
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Vertical Axis ◽  
Mesh Deformation ◽  
Operating Speed ◽  
Vertical Axis Wind Turbine ◽  
Vertical Axis Wind Turbines ◽  
Turbine Performance

Vertical axis wind turbines have always been a controversial technology; claims regarding their benefits and drawbacks have been debated since the initial patent in 1931. Despite this contention, very little systematic vertical axis wind turbine research has been accomplished. Experimental assessments remain prohibitively expensive, while analytical analyses are limited by the complexity of the system. Numerical methods can address both concerns, but inadequate computing power hampered this field. Instead, approximating models were developed which provided some basis for study; but all these exhibited high error margins when compared with actual turbine performance data and were only useful in some operating regimes. Modern computers are capable of more accurate computational fluid dynamics analysis, but most research has focused on horizontal axis configurations or modeling of single blades rather than full geometries. In order to address this research gap, a systematic review of vertical axis wind-power turbine (VAWT) was undertaken, starting with establishment of a methodology for vertical axis wind turbine simulation that is presented in this paper. Replicating the experimental prototype, both 2D and 3D models of a three-bladed vertical axis wind turbine were generated. Full transient computational fluid dynamics (CFD) simulations using mesh deformation capability available in ansys-CFX were run from turbine start-up to operating speed and compared with the experimental data in order to validate the technique. A circular inner domain, containing the blades and the rotor, was allowed to undergo mesh deformation with a rotational velocity that varied with torque generated by the incoming wind. Results have demonstrated that a transient CFD simulation using a two-dimensional computational model can accurately predict vertical axis wind turbine operating speed within 12% error, with the caveat that intermediate turbine performance is not accurately captured.

scholarly journals Investigasi Performa Turbin Angin Crossflow Dengan Simulasi Numerik 2D

2020 ◽  
Vol 8 (1) ◽  
pp. 7-12
Author(s):  
Diniar Mungil Kurniawati
Keyword(s):  
Numerical Simulation ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Turbine Blades ◽  
Slope Angle ◽  
Electrical Energy ◽  
Diameter Ratio ◽  
Cfd Modeling ◽  
Maximum Efficiency ◽  
Multiple Interactions

Wind turbine is a solution to harness of renewable energy because it requires wind as the main energy. Wind turbine work by extracting wind energy into electrical energy. Crossflow wind turbine is one of the wind turbines that are developed because it does not need wind direction to produce maximum efficiency. Crossflow wind turbines work with the concept of multiple interactions, namely in the first interaction the wind hits the first level of turbine blades, then the interaction of the two winds, the remainder of the first interaction enters the second level blades before leaving the wind turbine. In the design of crossflow wind turbine the diameter ratio and slope angle are important factors that influence to determine of performance in crossflow wind turbine. In this study varied the angle of slope 90 ° and variations in diameter ratio of 0.6 and 0.7. The study aimed to analyze the effect of diameter ratio and slope angle in performance of the crossflow wind turbine. This research was conducted with numerical simulation through 2D CFD modeling. The results showed that the best performance of crossflow wind turbine occurred at diameter ratio variation 0.7 in TSR 0.3 with the best CP value 0.34.

Flow Simulation Around a Rim-Driven Wind Turbine and in Its Wake

2013 ◽  
Author(s):  
Bryan E. Kaiser ◽  
Svetlana V. Poroseva ◽  
Michael A. Snider ◽  
Rob O. Hovsapian ◽  
Erick Johnson
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Wind Farm ◽  
Flow Simulation ◽  
Wind Farms ◽  
Sensitivity Study ◽  
Onshore Wind ◽  
Flow Simulations ◽  
Turbine Design ◽  
The Impact

A relatively high free stream wind velocity is required for conventional horizontal axis wind turbines (HAWTs) to generate power. This requirement significantly limits the area of land for viable onshore wind farm locations. To expand a potential for wind power generation and an area suitable for onshore wind farms, new wind turbine designs capable of wind energy harvesting at low wind speeds are currently in development. The aerodynamic characteristics of such wind turbines are notably different from industrial standards. The optimal wind farm layout for such turbines is also unknown. Accurate and reliable simulations of a flow around and behind a new wind turbine design should be conducted prior constructing a wind farm to determine optimal spacing of turbines on the farm. However, computations are expensive even for a flow around a single turbine. The goal of the current study is to determine a set of simulation parameters that allows one to conduct accurate and reliable simulations at a reasonable cost of computations. For this purpose, a sensitivity study on how the parameters variation influences the results of simulations is conducted. Specifically, the impact of a grid refinement, grid stretching, grid cell shape, and a choice of a turbulent model on the results of simulation of a flow around a mid-sized Rim Driven Wind Turbine (U.S. Patent 7399162) and in its near wake is analyzed. This wind turbine design was developed by Keuka Energy LLC. Since industry relies on commercial software for conducting flow simulations, STAR-CCM+ software [1] was used in our study. A choice of a turbulence model was made based on the results from our previous sensitivity study of flow simulations over a rotating disk [2].

scholarly journals A Fully Coupled Computational Fluid Dynamics Method for Analysis of Semi-Submersible Floating Offshore Wind Turbines Under Wind-Wave Excitation Conditions Based on OC5 Data

2018 ◽  
Vol 8 (11) ◽  
pp. 2314 ◽  
Author(s):  
Yin Zhang ◽  
Bumsuk Kim
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Wind Wave ◽  
Offshore Wind ◽  
Wave Excitation ◽  
Offshore Wind Turbines ◽  
Floating Offshore Wind Turbines ◽  
Fully Coupled

Accurate prediction of the time-dependent system dynamic responses of floating offshore wind turbines (FOWTs) under aero-hydro-coupled conditions is a challenge. This paper presents a numerical modeling tool using commercial computational fluid dynamics software, STAR-CCM+(V12.02.010), to perform a fully coupled dynamic analysis of the DeepCwind semi-submersible floating platform with the National Renewable Engineering Lab (NREL) 5-MW baseline wind turbine model under combined wind–wave excitation environment conditions. Free-decay tests for rigid-body degrees of freedom (DOF) in still water and hydrodynamic tests for a regular wave are performed to validate the numerical model by inputting gross system parameters supported in the Offshore Code Comparison, Collaboration, Continued, with Correlations (OC5) project. A full-configuration FOWT simulation, with the simultaneous motion of the rotating blade due to 6-DOF platform dynamics, was performed. A relatively heavy load on the hub and blade was observed for the FOWT compared with the onshore wind turbine, leading to a 7.8% increase in the thrust curve; a 10% decrease in the power curve was also observed for the floating-type turbines, which could be attributed to the smaller project area and relative wind speed required for the rotor to receive wind power when the platform pitches. Finally, the tower-blade interference effects, blade-tip vortices, turbulent wakes, and shedding vortices in the fluid domain with relatively complex unsteady flow conditions were observed and investigated in detail.

Review Paper on Wind Turbine Aerodynamics

2011 ◽  
Vol 133 (11) ◽  
Author(s):  
Martin O. L. Hansen ◽  
Helge Aagaard Madsen
Keyword(s):  
Fluid Dynamics ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Future Development ◽  
Review Paper ◽  
Wind Farms ◽  
Vortex Generators ◽  
Aerodynamic Loads ◽  
Wind Turbine Aerodynamics ◽  
Engineering Models

The paper describes the development and description of the aerodynamic models used to estimate the aerodynamic loads on wind turbine constructions. This includes a status of the capabilities of computation fluid dynamics and the need for reliable airfoil data for the simpler engineering models. Also a discussion of the use of passive and active aerodynamic devices is included such as, e.g., Vortex Generators and distributed active flaps. Finally the problem of wakes in wind farms is addressed and a section of the likely future development of aerodynamic models for wind turbines is included.

Optimization of Micro Wind Turbine for Dental Fiber Handpiece Based on the Taguchi Method

2012 ◽  
Vol 605-607 ◽  
pp. 401-404
Author(s):  
Kuang Hung Hsien ◽  
Shyh Chour Huang
Keyword(s):  
Fluid Dynamics ◽  
Electromagnetic Field ◽  
Taguchi Method ◽  
Wind Turbine ◽  
Fill Factor ◽  
Signal To Noise Ratio ◽  
Field Analysis ◽  
Halogen Lamp ◽  
Signal To Noise ◽  
Turbine Design

This paper presents the use of the Taguchi method, Computational-Fluid-Dynamics and electromagnetic field analysis to optimize the design of a micro wind turbine for a dental fiber handpiece. An orthogonal array, the signal-to-noise ratio and analysis of variance were used to study the multiple-objectives in the micro wind turbine design. The results showed that: (1) the wire slot fill factor and stator angle have a significant influence on the flow rate, whereas wire slot fill factor and inlet dimensions have a significant effect on the pressure drop; (2) the micro wind turbine reduces electricity usage by 25 watts in a day and produces brightness of 20,000-23,000 lux. The proposed design of the micro wind turbine not only saves energy but also reduces the need for replacement halogen lamp.

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