Design and Analysis of a Marine Current Turbine
07 Dec 2017-
About: The article was published on 2017-12-07. It has received 6 citations till now. The article focuses on the topics: Current (fluid) & Turbine.
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TL;DR: In this paper, a near-wake characterization study was performed using complementary acoustic Doppler velocimetry measurements and 3D computational fluid dynamics, which showed that the deflected wake morphed into an elliptical shape due to the formation of two counterrotating vortices.
9 citations
TL;DR: In this paper, a scaled horizontal axis marine current turbine was numerically simulated after validation and the turbine design was optimized using an in-house surrogate-based optimization (SBO) code.
Abstract: Flow through a scaled horizontal axis marine current turbine was numerically simulated after validation and the turbine design was optimized. The computational fluid dynamics (CFD) code Ansys-CFX 16.1 for numerical modeling, an in-house blade element momentum (BEM) code for analytical modeling and an in-house surrogate-based optimization (SBO) code were used to find an optimal turbine design. The blade-pitch angle (o) and the number of rotor blades (NR) were taken as design variables. A single objective optimization approach was utilized in the present work. The defined objective function was the turbine\'s power coefficient (Cp). A 3x3 full-factorial sampling technique was used to define the sample space. This sampling technique gave different turbine designs, which were further evaluated for the objective function by solving the Reynolds-Averaged Navier–Stokes equations (RANS). Finally, the SBO technique with search algorithm produced an optimal design. It is found that the optimal design has improved the objective function by 26.5%. This article presents the solution approach, analysis of the turbine flow field and the predictability of various surrogate based techniques.
7 citations
Cites methods from "Design and Analysis of a Marine Cur..."
...2) was implemented to reduce the CFD simulation time (Karthikeyan et al. 2017)....
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TL;DR: In this paper, numerical simulation is used to investigate a counter-rotating dual-rotor marine current turbine (MCT) that is aligned for a rectilinear tidal current, and results of power and thrust coefficients and the mean axial velocity in the wake are compared with that of the blade element momentum (BEM) method coupled with the Park wake model.
6 citations
TL;DR: In this paper, the shape optimization of a horizontal-axis MCT of 0.8m diameter was optimized through multi-fidelity numerical approach to increase the power coefficient and reduce the von-Mises stress.
Abstract: A marine current turbine (MCT) that extracts energy from ocean currents should be hydrodynamically and structurally stable to generate uninterrupted power. This can be achieved through the shape optimization of MCT blades. In this work, a horizontal axis MCT of 0.8 m diameter was optimized through multi-fidelity numerical approach. The design parameters such as blade pitch angle (θ) and the number of rotor blades (NR) were modified to increase the power coefficient (CP) and to reduce the von-Mises stress (σv) using multi-objective optimization technique. A coupled fluid–structure interaction method is used for fluid and structural analysis of MCT. Also, an analysis for identifying the cavitation inception is incorporated. A surrogate-based optimization code was used to produce a Pareto optimal front. The MCT with CP = 0.451 encountered σv = 125.83 MPa and a high total deformation (TD) = 20.259 mm near the blade tip. The TD of the same MCT blade was later reduced to 1/3rd of its actual value by identifying an alternate turbine material. The losses due to vortices, wake generation, and cavitation study are discussed in the present work.
3 citations
04 Jul 2018
TL;DR: In this article, the surface curvature effects on the performance of a 3D lab scale tidal turbine (E387) using Eppler 387 airfoil were analyzed using in-house BEM code and CFD RANS.
Abstract: This paper presents numerical study of the surface curvature effects on the performance of a 3D lab scale tidal turbine (E387) using Eppler 387 airfoil. The prescribed surface curvature distribution blade design method is used to remove the surface curvature discontinuity of E387 turbine and the redesigned turbine is denoted as A7 turbine. The two turbines are analysed using in-house BEM code and CFD RANS. The performance of E387 turbine obtained from BEM and RANS match well with the experimental results from reported literature. The A7 turbine has a mildly better performance at low tip speed ratios (1–4.25) where the rotor is deviated from the designed operating TSR and the blade is partly or fully stalled.
3 citations