Design of a hydrokinetic turbine (original) (raw)
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Energies
In this study, a hydrokinetic turbine is designed for the high-altitude regions where local electricity network lines are difficult to reach. If there was a stream flow around, electricity production could be possible and necessary because of environmental reasons. The performance of the hydrokinetic turbine was investigated experimentally and numerically. The numerical analyses of the turbine system were performed via MATLAB/Simulink version R2014a. Except power-based performance characteristics, efficiency of the system in terms of installation and necessary investment costs were also investigated. It is calculated that the system to be established on a river with a water flow rate of 30 m3/h will meet the investment cost in approximately 8 years.
Design of a hydrokinetic turbine capable of satisfying
Design of a hydrokinetic turbine capable of satisfying electricity demand for housing on the margin of the Magdalena river through analysis by finite elements, 2018
This research is aimed to design a hydrokinetic turbine for electric generation taking advantage of available energy of the Magdalena River, which has a great flow near to its mouth in the Atlantic Ocean of Northern Colombian. The turbine design consists of a tri-bladed horizontal axis turbine totally submerged; the rotor is fixed to a metallic platform with tanks acting as floats. It also contains an asynchronous electric engine as a generator and electrical lines. The turbine power shaft is transmitted to the engine by a system of toothed belts, which performs the role of gearbox and multiplier. As a result, CFD simulations shows several variables of interest in order to evaluate power generation, such as torque, angular velocity, power, turbine efficiency, and hydrokinetic and structural analysis are obtained by means of finite elements.
Many modifications have been made on conventional hydrokinetic turbines rotor blades to improve the performances. The rotor blade modification in this research paper is a blade combination where the circle-shaped conventional model is combined with the one of a concave elliptical model. Two different blade geometries have been analyzed using a detailed computational Fluid Dynamics approach. The blade design will affect the simplicity of construction and cost of manufacture of turbine rotors. The aim is to analyze the influence of the blade combination towards the performance of hydrokinetic turbine for installation at a selected site. The research includes experimental method using open-type water tunnel of rotor's prototype with 2 different blade models of similar dimensions. The experiment shows, there are influences of the modification of the rotor blade to the performances of the turbine. The optimized blade design improves the performances of the Tip Speed Ratio (TSR) by 78 % while the Coefficient of thrust (CT) is improved by 58.3% at peak co-efficient of performance value of 0.47 for both the blade designs.
Experimental study of a small-scale axial hydrokinetic turbine with adjustable blade pitch
A small-scale axial hydrokinetic turbine (HKT) with a runner having 3 blades with adjustable pitch and a diameter of 0.2 m was designed and tested to evaluate the optimum relationship between its power coefficient and its blade tip speed ratio (TSR). The design was carried out for a water velocity of 0.8 m/s and was based on the Blade Element Momentum Theory. The turbine was built by 3D printing and tested in a free surface water channel for water velocities between 0.8 and 1.1 m/s at three different blade pitch angles. The speed and torque at the turbine shaft were measured. The results of the experimental tests are encouraging and in good agreement with the literature and show that for harvesting hydrokinetic energy for power generation, fast HKTs with 3 thinner blades are more suitable than slower designs with wider blades, as the former allow a reduction in the size and cost of the electrical generator.
MATEC Web of Conferences, 2017
Booming population and associated energy demands, looming threat of exhaustion of conventional sources of energy and the severe environmental repercussions of the same call for alternate sources of clean energy. Hydrokinetic turbine is one such developing technology which harnesses zero-head free flow of water and affects hydrological ecology minimally. This paper discusses the optimisation of Horizontal Axis Hydrokinetic Turbine (HAHkT) blade chord length and twist angle using blade element momentum (BEM) theory to achieve a constant optimal angle of attack (AoA), thus maximising the power output. To achieve this while maintaining robustness at the hub end and eliminate cavitation, two different hydrofoils (S832 and E817) are selected. S832 is simulated using ANSYS 14.0 at low (0⁰) and high (15⁰) angles of attack and compared against more widely used NACA 4412 to study flow separation characteristics. This is followed by calculating angles of relative flow, ratios of chord length and subsequently twist angles for each blade element using MATLAB simulations. A blade model is thus developed for visualisation using computer aided designing after obtaining optimal chord lengths and pitch angles.
Journal of Renewable and Sustainable Energy, 2011
The hydrodynamic performance of horizontal axis hydrokinetic turbines (HAHkTs) under different turbine geometries and flow conditions is discussed. Hydrokinetic turbines are a class of zero-head hydropower systems which utilize kinetic energy of flowing water to drive a generator. However, such turbines very often suffer from low-efficiency which is primarily due to its operation in a low tip-speed ratio (4) regime. This makes the design of a HAHkT a challenging task. A detailed computational fluid dynamics study was performed using the k-x shear stress transport turbulence model to examine the effect of various parameters like tip-speed ratio, solidity, angle of attack, and number of blades on the performance HAHkTs having power capacities of $12 kW. For this purpose, a three-dimensional numerical model was developed and validated with experimental data. The numerical studies estimate optimum turbine solidity and blade numbers that produce maximum power coefficient at a given tip speed ratio. Simulations were also performed to observe the axial velocity ratios at the turbine rotor downstream for different tip speed ratios which provide quantitative details of energy loss suffered by each turbine at an ambient flow condition. The velocity distribution provides confirmation of the stall-delay phenomenon due to the effect of rotation of the turbine and a further verification of optimum tip speed ratio corresponding to maximum power coefficient obtained from the solidity analysis. V
Performance of a hydrokinetic turbine using a theoretical approach
Energy Reports, 2020
Regarding the interest in renewable energies, several sources of energy production have been studied and still under improvement. In this work, we are interested in harnessing marine energy currents exploiting the hydrokinetic turbines. The purpose of this study is to provide a comprehensive assessment of the hydrodynamic loads of a 3-blade horizontal-axis marine turbine using a rotor model adapted to the Moroccan potential. For that, the Blade Element Momentum (BEM) is used to calculate the hydrodynamic loads, to estimate the energetic performance, and to determine the blade optimal parameters for a turbine. In additions, the resulting equations are solved in order to obtain the hydrodynamic loads. For validation, a comparison of pressure coefficients along the chord length was made with the results of the Blade software. The Computations were accomplished for a specific NACA profile. c
DEVELOPMENT OF HYDROKINETIC POWER GENERATION SYSTEM: A REVIEW
Small scale hydropower is one of the renewable energy source of energy which has vast potential. Hydrokinetic turbines are suitable to tap this potential and the technology is recent which produces electricity from flowing water. Hydrokinetic turbines are more suitable to convert kinetic energy in the river and marine current. An extensive literature review has been carried out and presented in this paper. This paper basically summarizes existing hydrokinetic turbines and projects implemented so far. Based on literature review it is found that lot of work is being carried out on hydro kinetic turbines which are suitable to install at power channel, river and canal. However, optimum parameters for different types of hydro kinetic turbines have not been found to develop the standard size hydro kinetic turbines for different sites.
Engineering Journal, 2018
Three twisted blades of a 1 kW prototype hydrokinetic turbine were designed based on the Blade Element Momentum (BEM) theory with a tip speed ratio of 6.25; a water velocity of 1.5 m/s; an angle of attack and pitch angle of 5 and 0 • , respectively; a power coefficient of 0.4382 and a drive train efficiency of 70%. S822 hydrofoil was used to generate the coordinates of the blade cross-section. Experimental investigations and Computational Fluid Dynamics (CFD) simulations were carried out to estimate the performance of the blade design and know the effect of the section pitch angle on the performance of a horizontal-axis hydrokinetic turbine. The obtained results showed that the increase in the section pitch angle enhanced the performance up to a certain value. Further increase in the section pitch angle resulted in a low performance and a reduction of the rotation velocity, which in turn requires a high gearing ratio of the transmission system.
An Approach for the Dynamic Behavior of Hydrokinetic Turbines
Energy Procedia, 2015
The power generation, using hydrokinetic turbine, has been significantly studied in recent years. Such importance is due to the use of clean energy source with low environmental impact. That kind of technology converts the kinetic energy transported by marine and fluvial currents into mechanical energy and, consequently in electrical energy. Therefore, this work presents a methodology for the efficient design of small horizontal axis hydrokinetic turbines with variable rotation. The approach uses the dynamic equation of the power train, taking into account the Blade Element Method (BEM) for determining the power coefficient of the turbine, which is coupled with the model of the drive line of the system, including the multiplier and the electric generator. Thus, the modeling of the whole system comprises the hydrodynamic information of the rotor and the characteristics of the inertia of the system, frictional losses and electromagnetic torque of the generator. The results of numerical simulation are obtained for the transient rotational speed of the rotor and compared with field data measured from small hydrokinetic turbine.