Performance Characteristics of Vertical-Axis Off-Shore Savonius Wind and Savonius Hydrokinetic Turbines

2018 ◽  
Author(s):  
Parag K. Talukdar ◽  
Vinayak Kulkarni ◽  
Ujjwal K. Saha
Keyword(s):  
Energy Demand ◽  
Computational Study ◽  
Renewable Energy Sources ◽  
Electrical Power ◽  
Clean Energy ◽  
Vertical Axis ◽  
Input Power ◽  
Offshore Wind ◽  
Hydrokinetic Turbines ◽  
Hydrokinetic Turbine

The rise in energy demand, climate change and depletion of fossil fuel, encourages the researchers to find a solution to the scarcity of clean energy. Therefore, the extraction of energy from renewable energy sources has become a topic of interest in the past few decades across the globe. Thus, harvesting the offshore wind and hydro energy and converting it to electrical power using various electromechanical devices has been a challenge. In this context, the vertical-axis Savonius wind and Savonius hydrokinetic turbines appear to be promising concept for energy conversion because of their good self-starting capability and simplicity in design. The present study attempts to characterize the performances of a Savonius wind turbine (SWT) and a Savonius hydrokinetic turbine (SHT) under identical input flow conditions. In order to characterize their performances, the SWT is tested in a low-speed wind tunnel with closed test section whereas the SHT is tested in an open channel flume. In each case, the torque and power coefficients are estimated at different mechanical loading conditions. It is observed that the SWT and SHT demonstrate peak power coefficients of 0.25 and 0.28 respectively for the same input power. However, the SWT is found to operate over a slightly wider range of tip-speed ratios than the SHT before the onset of stall. Finally, the computational study using ANSYS 14.5 has been carried out to evaluate the flow physics of the turbine at various azimuthal positions.

Numerical Investigation to Assess an Optimal Blade Profile for the Drag Based Vertical Axis Wind Turbine

2013 ◽  
Author(s):  
Sukanta Roy ◽  
Ujjwal K. Saha
Keyword(s):  
Renewable Energy ◽  
Wind Energy ◽  
Wind Turbines ◽  
Energy Demand ◽  
Computational Study ◽  
Flow Behavior ◽  
Renewable Energy Sources ◽  
Vertical Axis ◽  
Small Scale ◽  
Vertical Axis Wind Turbine

Rapid depletion rate of fossil fuels with an increasing energy demand and their high emission are imposing the evolution activities in the arena of renewable energy. To meet the future demands of renewable energy sources, wind energy is a very promising concept. In this feature, the drag based vertical axis wind turbines (VAWTs) are suitable for small scale wind energy generation for decentralized locations. However, these turbines have low power and torque coefficients as compared to other wind turbines. Numerous blade shapes have been proposed till now to improve the performance of these turbines. In the present paper, a computational study has been performed to simulate the air-flow over different blade profiles using shear stress transport (SST) k–ω turbulence model. The results obtained are validated with the available experimental data. In the dynamic simulations, the power and torque coefficients are calculated considering the blade arc angle as the variable shape parameter. The effects of drag and lift forces on the variable blade shapes are also studied in static simulations at various angular positions. The present paper tries to demonstrate an effective computational methodology to predict the flow behavior around a drag based VAWT. Through this study, it has been found possible to select an optimal blade shape from the point of its aerodynamic performance.

Direct ammonia fueled solid oxide fuel cells: A comprehensive review on challenges, opportunities and future outlooks

2020 ◽  
pp. 70-91 ◽  
Author(s):  
Molla Asmare ◽  
Mustafa Ilbas
Keyword(s):  
Electric Power ◽  
Energy Demand ◽  
Renewable Energy Sources ◽  
Clean Energy ◽  
Performance Comparison ◽  
Optimum Operating ◽  
Practical Implementation ◽  
Human Society ◽  
Energy Access ◽  
Green Fuel

Nowadays, the most decisive challenges we are fronting are perfectly clean energy making for equitable and sustainable modern energy access, and battling the emerging alteration of the climate. This is because, carbon-rich fuels are the fundamental supply of utilized energy for strengthening human society, and it will be sustained in the near future. In connection with this, electrochemical technologies are an emerging and domineering tool for efficiently transforming the existing scarce fossil fuels and renewable energy sources into electric power with a trivial environmental impact. Compared with conventional power generation technologies, SOFC that operate at high temperature is emerging as a frontrunner to convert the fuels chemical energy into electric power and permits the deployment of varieties of fuels with negligible ecological destructions. According to this critical review, direct ammonia is obtained as a primary possible choice and price-effective green fuel for T-SOFCs. This is because T-SOFCs have higher volumetric power density, mechanically stable, and high thermal shocking resistance. Also, there is no sealing issue problem which is the chronic issues of the planar one. As a result, the toxicity of ammonia to use as a fuel is minimized if there may be a leakage during operation. It is portable and manageable that can be work everywhere when there is energy demand. Besides, manufacturing, onboard hydrogen deposition, and transportation infrastructure connected snags of hydrogen will be solved using ammonia. Ammonia is a low-priced carbon-neutral source of energy and has more stored volumetric energy compared with hydrogen. Yet, to utilize direct NH3 as a means of hydrogen carrier and an alternative green fuel in T-SOFCs practically determining the optimum operating temperatures, reactant flow rates, electrode porosities, pressure, the position of the anode, thickness and diameters of the tube are still requiring further improvement. Therefore, mathematical modeling ought to be developed to determine these parameters before planning for experimental work. Also, a performance comparison of AS, ES, and CS- T-SOFC powered with direct NH3 will be investigated and best-performed support will be carefully chosen for practical implementation and an experimental study will be conducted for verification based on optimum parameter values obtained from numerical modeling.

scholarly journals The Global Survey of the Electrical Energy Distribution System: A Review

2019 ◽  
Vol 9 (4) ◽  
pp. 2247 ◽  
Author(s):  
Archana Sudhakar Talhar ◽  
Sanjay B. Bodkhe
Keyword(s):  
Renewable Energy ◽  
Renewable Energy Sources ◽  
Electrical Power ◽  
Electrical Energy ◽  
Clean Energy ◽  
Central Intelligence Agency ◽  
Energy Sources ◽  
Power Sources ◽  
Energy Scenario ◽  
The World

This paper gives a review of energy scenario in India and other countries. Today’s demand of the world is to minimize greenhouse gas emissions, during the production of electricity. Henceforth over the world, the production of electrical power is changing by introducing abundantly available renewable energy sources like sun and wind. But, because of the intermittent nature of sustainable power sources, the electrical power network faces many problems, during the transmission and distribution of electricity. For resolving these issues, Electrical Energy Storage (EES) is acknowledged as supporting technology. This paper discusses about the world electrical energy scenario with top renowned developed countries in power generation and consumption. Contribution of traditional power sources changed after the introduction of renewable energy sources like sun and wind. Worldwide Agencies are formed like International Energy Agency (IEA), The Central Intelligence Agency, (CIS) etc. The main aim of these agencies is to provide reliable, affordable and clean energy. This paper will discuss about the regulatory authority and government policies/incentives taken by different countries.  At the end of this paper, author focuses on obstacles in implementation, development and benefits of renewable energy.

Computational Study of Multiple Hydrokinetic Turbines: The Effect of Wake

2015 ◽  
Author(s):  
Cosan Daskiran ◽  
Jacob Riglin ◽  
Alparslan Oztekin
Keyword(s):  
Computational Study ◽  
Relative Power ◽  
Cfd Simulations ◽  
Significant Drop ◽  
Hydrokinetic Turbines ◽  
Hydrokinetic Turbine ◽  
Wake Interactions ◽  
Sst Turbulence Model ◽  
Computational Fluid Dynamics Cfd ◽  
Turbine Design

Computational Fluid Dynamics (CFD) simulations have been conducted to investigate the performance of a predetermined propeller-based hydrokinetic turbine design in staggered and non-staggered placements for river applications. Actual turbine models were used instead of low fidelity actuator line or actuator disks for CFD simulations to achieve more reliable results. The k-ω Shear Stress Transport (SST) turbulence model was employed to resolve wall effects on turbine surface and to determine wake interactions behind the turbines. The wake interaction behind the upstream turbine causes significant drop on downstream turbine performance within non-staggered configuration. The upstream turbines in both staggered and non-staggered placement offers the same relative power of 0.96, while the relative power for downstream turbine is 0.98 for staggered installment and 0.16 for inline placement.

Ocean Energy in the Caribbean: Technology Review, Potential Resource and Project Locational Guidance

2021 ◽  
Author(s):  
Sweyn Johnston ◽  
John McGlynn ◽  
Veronica R. Prado ◽  
Joseph Williams
Keyword(s):  
Energy Demand ◽  
Clean Energy ◽  
Technical Note ◽  
Offshore Wind ◽  
Caribbean Region ◽  
Ocean Energy ◽  
Cooperation Agreement ◽  
The Caribbean ◽  
Ocean Thermal Energy ◽  
Technology Review

This publication assesses the potential for deployment of the leading Marine Renewable Energy (MRE) technologies including Fixed Offshore Wind, Floating Offshore Wind, Ocean Thermal Energy Conversion across nine Countries of Interest (COI) in the Caribbean region. This is achieved by conducting a technology review, analysing resource levels in each of the COIs, and presenting the outputs of Locational Guidance work identifying preferred areas for potential future project development. This work concludes that MRE can offer a secure supply of indigenous clean energy, that resources are sufficiently abundant to meet the current and future energy demand of each of the COIs many times over, and that the leading MRE technologies are sufficiently advanced to be worthy of immediate prioritisation. This Technical Note draws on and presents outcomes from work undertaken in 2019 as part of a Technical Cooperation Agreement between the IDB and CDB under the Support for Sustainable and Resilient Projects in the Caribbean programme.

Characteristics of the Wave Slamming Forces on Jacket Structures Under Plunging Breaking Waves Based on Experimental Data

2017 ◽  
Author(s):  
Jithin Jose ◽  
Olga Podrażka ◽  
Ove Tobias Gudmestad ◽  
Witold Cieślikiewicz
Keyword(s):  
Energy Demand ◽  
Clean Energy ◽  
Breaking Waves ◽  
Offshore Structures ◽  
Offshore Wind ◽  
Wave Forces ◽  
Breaking Wave ◽  
Jacket Structures ◽  
Wave Slamming ◽  
Wave Properties

Due to increased energy demand and thrive for clean energy, offshore wind energy has become popular these days. A large number of offshore wind turbines supported by fixed type substructures have been installed, among which jacket structures are getting popular in recent times. The forces from breaking waves are a major concern in the design of offshore structures installed in shallow waters. However, there are only limited studies available regarding breaking wave forces on jacket structures and still there exist many uncertainties in this area. During the WaveSlam experiment carried out in 2013, a jacket structure of 1:8 scale was tested on a large number of breaking wave conditions. Wave properties and the forces on the structure were measured during the experiment. The total wave slamming forces are being filtered from the experimental measured force using the Empirical Mode Decomposition method and local slamming forces are obtained by the Frequency Response Function method. Based on these results, the peak slamming force and slamming coefficients on the jacket members are estimated. The wave parameters (wave height and period) and wave front asymmetry are obtained from measured wave properties. The variation of slamming forces and slamming coefficients with respect to these parameters are also investigated.

scholarly journals Aerodynamic Simulations for Floating Darrieus-Type Wind Turbines with Three-Stage Rotors

Inventions ◽  
2020 ◽  
Vol 5 (2) ◽  
pp. 18
Author(s):  
Mohamed Amine Dabachi ◽  
Abdellatif Rahmouni ◽  
Eugen Rusu ◽  
Otmane Bouksour
Keyword(s):  
Wind Energy ◽  
Wind Turbines ◽  
Energy Demand ◽  
Fossil Fuels ◽  
Cost Effective ◽  
Vertical Axis ◽  
Offshore Wind ◽  
Critical Parameters ◽  
Vertical Axis Wind Turbine ◽  
Horizontal Axis Wind Turbines

Growing energy demand is causing a significant decrease in the world’s hydrocarbon stock in addition to the pollution of our ecosystem. Based on this observation, the search for alternative sorts of energy to fossil fuels is being increasingly explored and exploited. Wind energy is experiencing a very important development, and it offers a very profitable opportunity for exploitation since the wind is always available and inexhaustible. Several technical solutions exist to exploit wind energy, such as floating vertical axis wind turbines (F-VAWTs), which provide an attractive and cost-effective solution for exploiting higher resources of offshore wind in deep water areas. Recently, the use of the Darrieus vertical axis wind turbine (VAWT) offshore has attracted increased interest because it offers significant advantages over horizontal axis wind turbines (HAWTs). In this context, this article presents a new concept of floating Darrieus-type straight-bladed turbine with three-stage rotors. A double-multiple stream tube (DMST) model is used for aerodynamic simulations to examine several critical parameters, including, solidity turbine, number of blades, rotor radius, aspect ratio, wind velocity, and rotor height. This study also allows to identify a low solidity turbine (σ = 0.3), offering the best aerodynamic performance, while a two-bladed design is recommended. Moreover, the results also indicate the interest of a variable radius rotor, as well as the variation of the height as a function of the wind speed on the aerodynamic efficiency.

scholarly journals Challenges in Integrating Renewable Sources into a Utility Grid

2020 ◽  
Vol 9 (3) ◽  
pp. 91-97
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Large Scale ◽  
Renewable Energy Sources ◽  
Electrical Power ◽  
Clean Energy ◽  
Energy Sources ◽  
Electrical Power System ◽  
Renewable Sources ◽  
Utility Grid

In India, Electrical Power System is adapted to handle both constant loads and variable loads, also power is generated in two types; one is due to fossil fuels, and another one is due to renewable energy sources. However, renewable energy sources are playing a vital role in the production of clean energy and also useful for the reduction in greenhouse emission. Nevertheless, when there is any additional change in the generation side concerning to input supply, which is due to the uncertainty of nature, can create new challenges for the system operators and utility centers. It is not an easy task for the utility centres and supply operators to integrate variable renewable energy sources with the utility grid. This paper explores an overview of some operational techniques and solutions, which are helpful for high penetration of renewable energy sources such as solar and wind energy. It also explores operation, control management and challenges due to renewable energy when they integrated with the utility grid. By interfacing of renewable energy sources with a utility grid with proper management and control can provide bi-directional communication between suppliers and consumers smartly. The aim of integrating large scale renewable sources from transmission and distribution network into an existing system is to reduce the power quality issues, demand response, forecasting, peak demand, and improve network security, fast scheduling and dispatch, aiming towards smart grid technology for electrical power systems.

scholarly journals Reduction of Voltage Ripple in DC Link of Wind Energy Conservation System Using Modified DC-DC Boost Converter

2021 ◽  
Author(s):  
L. Hubert Tony Raj ◽  
R. Sivakumar ◽  
R. Akash ◽  
M. Anandha Chakravarthi
Keyword(s):  
Renewable Energy ◽  
Demand Curve ◽  
Renewable Energy Sources ◽  
Clean Energy ◽  
Vertical Axis ◽  
Power Converter ◽  
Solar Pv ◽  
Vertical Axis Wind Turbine ◽  
Energy Applications ◽  
Hybrid Renewable Energy

Renewable energy provisions must be extracted in a more resourceful way, with a power converter added to the mix. If the supply-demand curve rises with the seasons, it becomes clear that renewable energy sources are used to provide clean energy. This clean energy cannot be used on load directly due to fluctuating conditions, to solve this problem a modified DC to DC converter with a ripple-free output is introduced. The Vertical Axis Wind Turbine (VAWT) and Solar PV were combined to achieve a constant DC output in a hybrid renewable energy conversion system. For renewable energy applications, a redesigned converter with ripple-free output is used. The simulation is made under MATLAB/SIMULINK and experimental parameters were measured using a nominal prototype.

scholarly journals The Investigation of Savonius Type and Darrieus H Type Wind Turbine Simulation with Wind Speed Variable

2021 ◽  
Vol 1 (2) ◽  
pp. 19-26
Author(s):  
Wibby Aditya Putra Utama ◽  
Yohandri Bow ◽  
M. Syahirman Yusi
Keyword(s):  
Renewable Energy ◽  
Wind Speed ◽  
Wind Turbine ◽  
Energy Demand ◽  
Renewable Energy Sources ◽  
Electrical Energy ◽  
Vertical Axis ◽  
Renewable Energy Resources ◽  
Vertical Axis Wind Turbine ◽  
Fan Speed

The demand for electrical energy that continues to increase along with the advancement of civilization and also the increasing number of people as well as the reduced level of fulfillment and availability of non-renewable energy sources, it is necessary to have renewable energy resources that capable of fulfill these energy demand in a more environmental friendly. One of the natural energies that we can use is wind energy, which is easy to get and lasts continuously. This research examines the comparison of the power generated from the vertical axis wind turbine savonius type and darrieus H type. The wind that use in this research get from from the fan. The test is doing by varying the wind speed by adjusting the fan speed. The fan is directed to the wind turbine to rotate the wind turbine. To measure the wind speed produced by the fan, a digital anemometer is used. The result of this research is the relation data of voltage to rpm and voltage to wind speed of wind turbine.

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