Computational and Experimental analysis of a Counter-Rotating Wind Turbine system (original) (raw)
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In this paper, dual-rotor counter-rotating (CR) configurations of vertical axis wind turbines (VAWT) are briefly inspected and divided into three types. This investigation was focused on one of these types – the CR-VAWT with co-axial rotors, in which two equal rotors are placed on the same shaft, displaced from each other along it and rotate in opposite directions. For this CR-VAWT with three-blade H-Darrieus rotors, the properties of the design in terms of aerodynamics, mechanical transmission and electric generator, as well as control system are analyzed. A new direct-driven dual-rotor (DR) permanent magnet synchronous generator (PMSG) was proposed, in which two built-in low-power PM electric machines have been added. They perform two functions – start-up and overclocking of the rotors to the angular velocity at which the lifting force of the blades is generated and stabilizing the CR-VAWT work as wind gusts act on the two rotors. Detailed in this paper is the evaluation of aerody...
Proceedings of the 5th World Congress on New Technologies, 2019
In this paper, results of the investigation on the performance of a small counter-rotating wind turbine has been presented. Computational Fluid Dynamics methods have been used for wind turbine simulations. Rotors representation were introduced into computational domain by means of Actuator Line Model. Influence of an axial distance of CRWT rotors has been investigated. In all studied configurations rotors were counter-rotating with exactly the same rotational speed. Results of a study revealed noticeable increase in power coefficient for optimal configuration. Dynamic interaction between rotors has been investigated exposing significant interference in both torque and power in part of considered cases. Reasonable rotors distances, as well as rotors placements on tower's sides have been proposed. Used calculation method has been found to be appropriate for counter-rotating wind turbine simulation.
Parametric Study on a Performance of a Small Counter-Rotating Wind Turbine
Energies, 2020
A small Counter-Rotating Wind Turbine (CRWT) has been proposed and its performance has been investigated numerically. Results of a parametric study have been presented in this paper. As parameters, the axial distance between rotors and a tip speed ratio of each rotor have been selected. Performance parameters have been compared with reference to a Single Rotor Wind Turbine (SRWT). Simulations were carried out with Computational Fluids Dynamics (CFD) solver and a Large Eddy Scale approach to model turbulences. An Actuator Line Model has been chosen to represent rotors in the computational domain. Summing up the results of simulation tests, it can be stated that when constructing a CRWT turbine, rotors should be placed at a distance of at least 0.5 D (where D is rotor outer diameter) or more. One can then expect a noticeable power increase compared to a single rotor turbine. Placing the second rotor closer than 0.5 D guarantees a significant increase in power, but in such configuratio...
The computational fluid dynamics performance analysis of horizontal axis wind turbine
International Journal of Power Electronics and Drive Systems (IJPEDS), 2019
Computational fluid dynamics (CFD) simulations were performed in the present study using ANSYS Fluent 18.0, a commercially available CFD package, to characterize the behaviour of the new HAWT. Static three-dimensional CFD simulations were conducted. The static torque characteristics of the turbine and the simplicity of design highlight its suitability for the GE 1.5xle turbine. The major factor for generating the power through the HAWT is the velocity of air and the position of the blade angle in the HAWT blade assembly. The paper presents the effect of The blade is 43.2 m length and starts with a cylindrical shape at the root then transitions to the airfoils S818, S825 and S826 for the root, body and tip respectively. This blade also has pitch to vary as a function of radius, giving it a twist and the pitch angle at the blade tip is 4 degrees. This blade was created to be similar in size to a GE 1.5xle turbine by Cornell University. In addition, note that to represent the blade being connected to a hub, the blade root is offset from the axis of rotation by 1 meter. The hub is not included in our model. The experimental analysis of GE 1.5xle turbine, so that possible the result of CFD analysis can be compared with theoretical calculations. CFD workbench of ANSYS is used to carry out the virtue simulation and testing. The software generated test results are validated through the experimental readings. Through this obtainable result will be in the means of maximum constant power generation from HAWT.
Numerical investigation on the performance of a small counter-rotating wind turbine
E3S Web of Conferences, 2019
The article presents results of the investigation on the performance of a small counter-rotating wind turbine. Wind turbine has been simulated using Computational Fluid Dynamics methods. Actuator Line Model has been successfully used to represent rotors in computational domain. Parametric study has been carried out, taking into account changes in the tip speed ratio of the rotors while maintaining a constant distance between upwind and downwind rotor. Study results revealed noticeable increase in power coefficient for optimal configuration. Dynamic interaction between rotors has been investigated exposing no significant interference in both torque and power.
Preliminary design and testing of VAWT blade for low wind speed using CFD
Journal of Physics: Conference Series
This research aims to study and design vertical-axis wind turbine (VAWT) for low wind speed using computational fluid dynamics (CFD) program called ANSYS ® Academic Student Release 19. 2. The wind turbine type used is of Savonius type with some parts being modified in order to optimize its rotation in the simulation. The simulation setup is to place the turbine in the middle of the wind tunnel, using initial wind speed of 5 m/s. The turbine itself has dimension of 20 cm of height, 10 cm of radius and 0.15 cm of thickness. These simulation data are used to analyses wind flow dynamics, rotational speed of the turbine, tip speed ratio and Reynolds number of this design. It found that the angular velocity is 200 rpm or 20.94 rad/s, tip speed ratio is 0.41 while Reynolds number is in turbulent flow of 6,798,002.
Computational Analysis of 30 Kw Contra Rotor Wind Turbine
2012
The aim of this study is to optimize and analyze the characteristics of the upwind primary rotor and the downwind secondary rotor of the contra rotor wind turbine to increase the aerodynamic performance by using computational fluid dynamic (CFD). The main objective is to provide maximum energy that can be extracted by the primary and secondary rotor from the renewable resource of wind to increase the thrust power. For this purpose, two kinds of rotor configurations which are 3-bladed single and 3-bladed contra-rotating rotor were compared by using CFD. The results of the primary and secondary rotor are validated with measurements of the 30 KW Contra rotor wind turbine available on literature and plotted for power output. The optimum axial distance between the two rotors are investigated through CFD for increased performance. In addition, the increased thrust and torque for each rotor configuration are compared for aerodynamic feasibility.
Development of an Experimental Setup for Double Rotor HAWT Investigation
Volume 6: Oil and Gas Applications; Concentrating Solar Power Plants; Steam Turbines; Wind Energy, 2012
An experimental set-up was designed and constructed to study the performance of single and double rotor Horizontal Axis Wind Turbines (HAWT) configurations. Different tip speed ratios (TSR) were tested under varying wind loadings. The experimental study was carried out in order to investigate the HAWT performance and thereby increase its aerodynamics efficiency. Another setup was built to measure the torque rotational speed characteristic of the generator. The double rotor configuration was chosen intentionally to study the efficiency improvements when the second downstream rotor extracts the kinetic energy dismissed by the upstream rotor. The study showed that the power coefficient can be indeed increased about 50 % with a double rotor HAW T configuration, and the power gained from a counter rotating rotor is higher than that of a co-rotating rotor owing to the effect of the wake of the upstream rotor. In addition, a theoretical analysis of wake effect of the upstream rotor on the downstream rotor including the effect of the distance between the two rotors on the total power coefficient was made and investigated experimentally in order to estimate the optimum distance between the two rotors.
Computational and Experimental Study on Vertical Axis Wind Turbine in Search for an Efficient Design
2014
Wind alone can fulfill most of the energy requirement of the world by its efficient conversion in to energy. Though Horizontal Axis Wind Turbine (HAWT) is more popular but needs high wind speed to generate energy. On the other hand Vertical Axis Wind Turbine (VAWT) needs low wind speed and can be installed anywhere which are some of the reasons for this research. The main objective of this research is to improve the design and performance of VAWT to make it more attractive, efficient, durable and sustainable. For a VAWT the blades perform the main role to extract energy from the wind. Airfoil is considered as the blade for this new design of VAWT. Airfoil has some good aerodynamic characteristics, match with the characteristics of Savonius type VAWT, such as good stall characteristics and little roughness effect, relatively high drag and low lift coefficient. Integration of Computational Fluid Dynamics (CFD) simulation and wind tunnel experimentation has made the current research more acceptable. 3-Dimensional CAD models of various simple airfoils have been designed in Solidworks. Using these airfoils and other shape, CFD simulation has been performed with five different VAWT designed models. Moving mesh and fluid flow simulation have been developed in CFD software FLUENT. The findings of these numerical simulations provided pressure contour, velocity contour, drag coefficient, lift coefficient, ii torque coefficient and power coefficient for all these models. Physical models of NACA5510, NACA7510 and semicircular rotors of three bladed are fabricated and tested inhouse subsonic wind tunnel. From these experiments dynamic torque has been measured using dynamic torque sensors for all these models at three different speeds. By comparing the numerical and experimental results it can be concluded that NACA7510 air foiled VAWT model gives the better performance at higher Tip Speed Ratio than other two models.
The effect of axial distance on dual rotor wind turbine’s performance
Journal of Physics: Conference Series, 2019
Dual-rotor wind turbine (DRWT) is the development of wind turbine design with the addition of rotors placed on the same shaft. The addition of rotors causes the turbine to improve its performance. Experimental research was conducted to determine the performance that can be achieved by the DRWT type using the wind tunnel module. The test was carried out on three variations of the axial distance ratio of 0.08; 0.12; and 0.16. Comparing with a singlerotor wind turbine (SRWT), the DRWT type gives better performance. The DRWT type can rotate at a lower tip speed ratio than SRWT type. The power generated by the DRWT type is increasing up to 100% at tip speed ratio of 0.08 in all axial distance ratio while SRWT type can not rotate at tip speed ratio of 0.8. The DRWT type with a ratio of 0.12 is able to reach the highest coefficient of power which is 0.35 at tip speed ratio of 1.2. There was an increment of 53.7% in mechanical power from the SRWT type under the same conditions. Furthermore,...