Hydrodynamic Design and Analysis of Horizontal Axis Marine Current Turbines With Lifting Line and Panel Methods

2011 ◽  
Author(s):  
J. Baltazar ◽  
J. Machado ◽  
J. A. C. Falca˜o de Campos
Keyword(s):  
Computational Models ◽  
Design Procedure ◽  
Horizontal Axis ◽  
Complete Analysis ◽  
Speed Ratio ◽  
Integral Boundary ◽  
Power Extraction ◽  
Marine Current ◽  
Lifting Line ◽  
Blade Geometry

This paper presents the computational models used by the authors at MARETEC/IST for hydrodynamic design and analysis of horizontal axis marine current turbines. The models combine a lifting line method for the optimization of the turbine blade geometry and an Integral Boundary Element Method (IBEM) for the hydrodynamic analysis. The classical lifting line optimization is used to determine the optimum blade circulation distribution for maximum power extraction. Blade geometry is determined with simplified cavitation requirements and limitations due to mechanical strength. The application of the design procedure is illustrated for a two-bladed 300 kW marine current turbine with a diameter of 11 meters. The effects of design tip-speed-ratio and the influence of blade section foils on power and cavitation inception are discussed. A more complete analysis may be carried out with an IBEM in steady and unsteady flow conditions. The IBEM has been extended to include wake alignment. The results are compared with experimental performance data available in the literature.

Computational Models for Prediction of Performance and Design of Tidal Turbines

2010 ◽  
Author(s):  
Spyros A. Kinnas ◽  
Wei Xu ◽  
Yi-Hsiang Yu
Keyword(s):  
Computational Models ◽  
Vortex Lattice ◽  
Design Procedure ◽  
Lattice Method ◽  
Vortex Lattice Method ◽  
Tidal Turbines ◽  
Unsteady Wake ◽  
Tidal Turbine ◽  
Wake Alignment ◽  
Lifting Line

In this paper, the performance of a horizontal axis, 3-blade tidal turbine is predicted by a vortex lattice method, in which the fully unsteady wake alignment is utilized to model the trailing wake geometry. A blade design procedure, which combines a lifting line approach with the vortex lattice analysis method and a nonlinear optimization scheme, is proposed.

scholarly journals Performance Analysis of Small Horizontal Axis Wind Turbine with Airfoil NACA 4412

2021 ◽  
Vol 2 (1) ◽  
pp. 347-357
Author(s):  
Syam Widiyanto ◽  
Sasongko Pramonohadi ◽  
Mohammad Kholid Ridwan
Keyword(s):  
Wind Turbine ◽  
Turbine Rotor ◽  
Horizontal Axis ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Horizontal Axis Wind Turbine ◽  
Integral Boundary ◽  
Low Wind Speed ◽  
A Value ◽  
Optimal Power

The horizontal axis wind turbine (HAWT) design with low wind speed requires blade geometry selection. The analysis uses the potential flow panel method and the integral boundary layer formulation to analyze wind flow around the airfoil. The blade design with the blade element momentum (BEM) theory has an aerodynamic coefficient value along the blade. Power wind calculates to model the wind shear pressure at each blade. This research aims to determine the wind turbine rotor based on the performance, including the power coefficient, tip speed ratio, power, and rpm. The simulation uses an airfoil NACA 4412 which has optimal coefficient lift (Cl) = 1.92 at 190 pitch of angle, coefficient drag (Cd) = 0.0635 at 130 pitch angle and Cl / Cd = 155 at tilt angle = 40. Five models of 2.5 m diameter blades with different angles for each chord. The test results show that the change in the speed ratio affects the power coefficient so that the optimal power coefficient on NACA 4412 in experiment 5 is 0.56, and change in rotation per minute affects the output power so that the rotation per minute and the optimal power in experiment 4 with a value of 374 rpm and 553 W.

scholarly journals Hydrodynamic Assessment of a Dual-Rotor Horizontal Axis Marine Current Turbine

2018 ◽  
Vol 7 (4.10) ◽  
pp. 455 ◽  
Author(s):  
EJ Avital ◽  
K Ai ◽  
N Venkatesan ◽  
A Samad ◽  
T Korakianitis
Keyword(s):  
Horizontal Axis ◽  
Hydrodynamic Performance ◽  
Medium Size ◽  
Speed Ratio ◽  
Power Gain ◽  
Performance Variation ◽  
Marine Current Turbine ◽  
Marine Current ◽  
Wake Model ◽  
Current Turbine

The hydrodynamic performance of a dual-rotor horizontal axis marine turbine (HAMCT) is investigated for the power gain in operating the rear rotor without blade-pitch control. This kind of turbine can be advantageous for a rectilinear tidal current of reversing directions, where each rotor blade is optimally fixed-pitched towards its upstream velocity. The blade element momentum (BEM) method is coupled with the Park wake model. A generic three-blade turbine is shown to gain up to 20% in the coefficient of power CP as relative to the front rotor CP when operating the rear rotor at the same tip speed ratio (TSR) as the front one, gaining overall CP up to 0.55. Analytic model is derived to backup the estimate of power gain. Plots for turbine performance variation with TSR and profile hydrodynamic efficiency are given, and analysed for lab and small-medium size turbines.  

scholarly journals A Model for Performance Estimation of Flapping Foil Operating as Biomimetic Stream Energy Device

2020 ◽  
Vol 9 (1) ◽  
pp. 21
Author(s):  
Iro E. Malefaki ◽  
Kostas A. Belibassakis
Keyword(s):  
Vertical Axis ◽  
Flow Speed ◽  
Performance Estimation ◽  
Speed Ratio ◽  
Power Extraction ◽  
Flapping Foil ◽  
Flow Energy ◽  
Novel Concept ◽  
Angular Oscillations ◽  
Energy Converters

During the recent period intensive research has focused on the advancement of engineering and technology aspects concerning the development and optimization of wave and current energy converters driven by the need to increase the percentage of marine renewable sources in the energy-production mix, particularly from offshore installations. Most stream energy-harvesting devices are based on hydro-turbines, and their performance is dependent on the ratio of the blade-tip speed to incident-flow speed. As the oncoming speed of natural-occurring currents varies randomly, there is a penalty for the latter device’s performance when operating at non-constant tip-speed ratio away from the design value. Unlike conventional turbines that are characterized by a single degree of freedom rotating around an axis, a novel concept is examined concerning hydrokinetic energy converters based on oscillating hydrofoils. The biomimetic device includes a rotating, vertically mounted, biomimetic wing, supported by an arm linked at a pivot point on the mid-chord. Activated by a controllable self-pitching motion the system performs angular oscillations around the vertical axis in incoming flow. In this work, the performance of the above flapping-foil, biomimetic flow energy harvester is investigated by application of a semi-3D model based on unsteady hydrofoil theory and the results are verified by comparison to experimental data and a 3D boundary element method based on vortex rings. By systematical application of the model the power extraction and efficiency of the system is presented for various cases including different geometric, mechanical, and kinematic parameters, and the optimal performance of the system is determined.

Wind Tunnel Tests of a Model Small-scale Horizontal-axis Wind Turbine Developed from Blade Element Momentum Theory

2021 ◽  
pp. 1-16
Author(s):  
Ojing Siram ◽  
Niranjan Sahoo ◽  
Ujjwal K. Saha
Keyword(s):  
Wind Tunnel ◽  
Horizontal Axis ◽  
Superior Performance ◽  
Speed Ratio ◽  
Small Scale ◽  
Blade Design ◽  
Horizontal Axis Wind Turbine ◽  
Blade Element Momentum Theory ◽  
Momentum Theory ◽  
Blade Element

Abstract The small-scale horizontal-axis wind turbines (SHAWTs) have emerged as the promising alternative energy resource for the off-grid electrical power generation. These turbines primarily operate at low Reynolds number, low wind speed, and low tip speed ratio conditions. Under such circumstances, the airfoil selection and blade design of a SHAWT becomes a challenging task. The present work puts forward the necessary steps starting from the aerofoil selection to the blade design and analysis by means of blade element momentum theory (BEMT) for the development of four model rotors composed of E216, SG6043, NACA63415, and NACA0012 airfoils. This analysis shows the superior performance of the model rotor with E216 airfoil in comparison to other three models. However, the subsequent wind tunnel study with the E216 model, a marginal drop in its performance due to mechanical losses has been observed.

Design and Optimization of a Ducted Marine Current Savonius Turbine for Gun-Barrel Passage, Fiji

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Jai Nendran Goundar ◽  
M. Rafiuddin Ahmed ◽  
Young-Ho Lee
Keyword(s):  
Flow Characteristics ◽  
Maximum Efficiency ◽  
Speed Ratio ◽  
Water Stream ◽  
Freestream Velocity ◽  
Design And Optimization ◽  
Gun Barrel ◽  
Marine Current ◽  
Ducted Turbine ◽  
Shaft Power

Marine current energy is a reliable and clean source of energy. Many marine current turbines have been designed and developed over the years. Placement of an appropriately designed duct or shroud around the turbine significantly improves the turbine performance. In the present work, a ducted Savonius turbine (DST) is designed and optimized and its performance analysis carried out. The components of DSTs are simple and easily available and can be manufactured in developing countries like Fiji. A scaled-down model of 1/20 of a DST was fabricated and tested in a water stream at a velocity of 0.6 m/s and the results were used to validate the results from a commercial computational fluid dynamics (CFD) code ANSYS-cfx. Finally, a full-scale DST was modeled to study the flow characteristics in the turbine and the performance characteristics. The maximum efficiency of the turbine is around 50% at the tip speed ratio (TSR) of 3.5 and the maximum shaft power obtained is 10 kW at the rated speed of 1.15 m/s and around 65 kW at a freestream velocity of 2.15 m/s. The stress distribution on the ducted turbine was also obtained.

scholarly journals New airfoils for micro horizontal-axis wind turbines

2021 ◽  
Author(s):  
Manoj Kumar Chaudhary ◽  
◽  
S. Prakash ◽  
Keyword(s):  
Reynolds Number ◽  
Wind Turbines ◽  
Low Reynolds Number ◽  
Horizontal Axis ◽  
Speed Ratio ◽  
Maximum Output ◽  
Horizontal Axis Wind Turbine ◽  
Horizontal Axis Wind Turbines ◽  
Low Reynolds ◽  
Bem Theory

In this study, small horizontal-axis wind turbine blades operating at low wind speeds were optimized. An optimized blade design method based on blade element momentum (BEM) theory was used. The rotor radius of 0.2 m, 0.4 m and 0.6 m and blade geometry with single (W1 & W2) and multistage rotor (W3) was examined. MATLAB and XFoil programs were used to implement to BEM theory and devise a six novel airfoil (NAF-Series) suitable for application of small horizontal axis wind turbines at low Reynolds number. The experimental blades were developed using the 3D printing additive manufacturing technique. The new airfoils such as NAF3929, NAF4420, NAF4423, NAF4923, NAF4924, and NAF5024 were investigated using XFoil software at Reynolds numbers of 100,000. The investigation range included tip speed ratios from 3 to 10 and angle of attacks from 2° to 20°. These parameters were varied in MATLAB and XFoil software for optimization and investigation of the power coefficient, lift coefficient, drag coefficient and lift-to-drag ratio. The cut-in wind velocity of the single and multistage rotors was approximately 2.5 & 3 m/s respectively. The optimized tip speed ratio, axial displacement and angle of attack were 5.5, 0.08m & 6° respectively. The proposed NAF-Series airfoil blades exhibited higher aerodynamic performances and maximum output power than those with the base SG6043 and NACA4415 airfoil at low Reynolds number.

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