Numerical investigation of the power generation of a ducted composite material marine current turbine (original) (raw)
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A novel design and preliminary investigation of composite material marine current turbine
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Numerical investigation on composite material marine current turbine using CFD
A novel manufacturing approach similar to filament winding has been developed and automated and is able to produce the Composite Material Marine Current Turbines (CMMCT), which have significant advantages over traditional designs. This paper presents numerical results to investigate the performance of these turbines. The numerical approach was performed using Computational Fluid Dynamics (CFD) in a free stream of water with various hydrodynamic flow conditions. Static torque, extracted power and power coefficient were calculated at different rotating speeds in a free stream with various hydrodynamics flow conditions. The power coefficient of CMMCT was compared to that of traditional current turbines. The calculated results will provide a fundamental understanding of the impeller as a water turbine, and this design method is used to shorten the design process and improve the water turbine’s performance.
The present paper deals with the flow distribution and power generation of ducted Composite Material Marine Current Turbines (CMMCTs) using Computational Fluid Dynamics (CFD). The hydrodynamic performance of CMMCTs in different array arrangement and the influence on each other were investigated and discussed. The numerical results showed the detail of flow distribution in arrays and provided an insight into the design and operation of CMMCTs in order to improve the technical performance. The methodology in the present study may be used to optimize the arrangement of the CMMCTs for possible maximum power generation.
Performance Analysis of Diffuser-Augmented Composite Marine Current Turbine Using CFD
2011
ABSTRACT A wound composite material wheel has been developed and is intended to be used for many purposes. One of these applications is marine current turbine. Diffuser-augmented turbines are capable of concentrating the energy in water. If a diffuser shaped shroud encloses a conventional horizontal axis turbine, the low pressure at the exit of the diffuser draws a larger mass flow through the turbine. This permits more power to be extracted from the water.
Numerical investigation of bare and ducted horizontal axis marine current turbines
The marine current turbine is the mechanical device that captures the kinetic energy of marine current to generate electrical power. This paper presents the application of an academic panel method code based on potential flow theory for the analysis of marine current turbines and the proposition of full scale bare and ducted design. The aim of this work is also to analyze the effect of the addition of a duct at the same overall section with bare turbine on the hydrodynamic performance. The numerical results show that the ducted turbine’s power coefficient, computed on the overall cross section, can be slightly increased through the use of a camber duct profile.
DESIGN OF COMPOSITE DUCTED HORIZONTAL AXIS TIDAL TURBINE
DESIGN OF COMPOSITE DUCTED HORIZONTAL AXIS TIDAL TURBINE
The marine current turbine is the mechanical device that captures the kinetic energy of marine current to generate electrical power. A panel method program coupled with the blade element momentum theory (BEM) was used to design a bare tidal turbine which reaches 88% of the Betz limit. The addition of a duct for a same overall cross section area has been investigated. The numerical results show that the ducted turbine’s power coefficient, which was computed using the overall cross section area, can be slightly increased if a camber duct profile with a flare angle is used. The hydrodynamic pressure obtained with the panel method code were then implemented as boundary conditions to a finite element analysis (FEA) in order to compute the mechanical behavior, stress distribution and deflection of the duct in composite material. The Hashin criterion was used for damage prediction.
Design of bare and ducted axial marine current turbines
To convert the kinetic energy of marine current into electricity, the most sensible generator is a horizontal axis turbine. The know-how and the tools used for marine propulsion devices find a new range of applications in this field. An academic panel method code developed for the design of bare and ducted marine propellers was applied to design a marine current turbine. The turbine dimension and the tidal current velocity have been taken to fit the conditions in the Race of Alderney. The wing section theory and the optimum rotor theory based on the blade element momentum were used to obtain the design condition and a first geometry approaching the Betz limit for a bare rotor. The panel method was then used to verify the power coefficient obtained in the presence of the 3D effects and if the cavitation constraints are respected. Subsequently, the same panel code was used to verify if the addition of a duct could improve the power output per unit surface.
An innovative configuration for new marine current turbine
Researchers have shown growing interest in the development of traditional Savonius turbine due to their numerous benefits such as structural simplicity, self-start ability, relatively low operating speed, bi-directional rotational ability and lower environmental impact. However, Savonius turbines exhibits lower efficiency as compared to other similar marine current turbines. This paper proposes a novel design concept for the Savonius turbine. In addition, this work investigates flow and pressure distribution around the buckets of novel rotor with a two-dimensional unsteady numerical model. The proposed marine current turbine with novel design is named as Reza Turbine. Numerical model employed the Dynamic Mesh Method (DMM) for modelling mesh movement around the blades of rotor for different position with respect to computational domain. Developed numerical model solves the unsteady Reynolds averaged Navier-Stokes equations by using SIMPLE algorithm. In addition, we conducted an experiment in a low speed wind tunnel to obtain important performance parameters namely torque, power and performance for the proposed turbine. A set of flow speed were used as inlet boundary condition for both numerical and experimental model. A comparison between numerical and experimental results shows that the SST k-u turbulence model gives satisfactory results for the developed novel turbine. The developed ReT is showed 52% improvement in efficiency as compared conventional Savonious turbine. Since the peak of power coefficient obtained was 0.321 for ReT, while 0.21 was reported for conventional Savonius turbine.
Design of a Ducted Cross-Flow Turbine for Marine Current Energy Extraction
Volume 6A: Energy, 2018
Marine current energy is a clean energy source and is a solution to the problems faced by burning fossil fuels such as global warming and climate change. Once tapped, the useful shaft power can be converted into electrical energy. To make this practical, the designed energy converter should be capable of operating at low marine current velocities, it should be suitable for installation at locations that have low water depths and should have lower manufacturing, installation and maintenance costs. A ducted cross-flow turbine has all the above features and it will be suitable for Pacific Island countries (PICs) for extracting marine current energy. The ducted cross-flow turbine was designed, modelled and analyzed in commercial Computational Fluid dynamic (CFD) code ANSYS-CFX. The inlet and outlet duct sizes were optimized for maximum output. Before the analysis of full model, the CFD results were validated with experimental results. Simulations for the 1:10 ducted cross-flow turbine (...