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Aerodynamic loads acting on different VAWT blades in X-and Y-directions: (a) H-type VAWT in the X-direction; (b) H-type VAWT in the Y-direction; (c) hybrid VAWT in the X-direction; and (d) hybrid VAWT in the Y-direction.
Source publication
Vertical-axis wind turbines (VAWTs) are compact and efficient and have become increasingly popular for wind energy harvesting. This paper mainly focuses on free and forced vibration analysis of two different types of VAWTs, i.e., an H-type VAWT and a new hybrid VAWT. The H-type VAWT has a lower cost, while the hybrid VAWT has a better self-starting...
Contexts in source publication
Context 1
... the simulation, the angular velocity of the two VAWTs is set to 16.625 rad/s when the wind speed is 5 m/s at the steady operational status and the corresponding TSR is 2.3. Time histories of aerodynamic loads on three outer blades (i.e., blades 1, 2, and 3) of the two VAWTs and inner blades of the hybrid VAWT are shown in Figure 8. Note that the free stream direction is denoted as the X-direction, and the direction perpendicular to the free stream and within the cross-sectional plane of a turbine is denoted as the Y-direction. ...
Context 2
... aerodynamic loads at any specific time are calculated via integration of both the pressure and viscous forces over blade surfaces. In Figure 8, blue solid lines, black dashed lines, and red dotted lines represent forces on the three outer blades, green two-dot chain lines represent forces on the three inner blades of the hybrid VAWT, and navy-blue solid lines represent resultant forces on all the blades of the two VAWTs. All these forces periodically vary with time. ...
Context 3
... the simulation, the angular velocity of the two VAWTs is set to 16.625 rad/s when the wind speed is 5 m/s at the steady operational status and the corresponding TSR is 2.3. Time histories of aerodynamic loads on three outer blades (i.e., blades 1, 2, and 3) of the two VAWTs and inner blades of the hybrid VAWT are shown in Figure 8. Note that the free stream direction is denoted as the X-direction, and the direction perpendicular to the free stream and within the crosssectional plane of a turbine is denoted as the Y-direction. ...
Context 4
... aerodynamic loads at any specific time are calculated via integration of both the pressure and viscous forces over blade surfaces. In Figure 8, blue solid lines, black dashed lines, and red dotted lines represent forces on the three outer blades, green two-dot chain lines represent forces on the three inner blades of the hybrid VAWT, and navy-blue solid lines represent resultant forces on all the blades of the two VAWTs. All these forces periodically vary with time. ...
Citations
... Recent studies have developed an intelligent blade pitch control system which can adjust the blade pitch angle based on the given parameters [12]. Another way to adjust the blade pitch angle is by using a passive control system which normally shows less performance when compared to the active system [7,13] Complicated aerodynamics due to the changing in AOA and azimuth position. Constant radius over the rotor span. ...
... Vibration analysis and structural health monitoring (SHM) of gearboxes are critical aspects of modern mechanical engineering, particularly in the context of predictive maintenance and system reliability [26,27]. Gearboxes, being complex mechanical systems with multiple moving parts, are prone to various failure modes such as tooth wear, pitting, cracking, and bearing defects [28,29,30,31,32,33]. ...
A novel automatic transmission that achieves power-on shifting with only one friction clutch, i.e., an overrunning clutch shift-assistant transmission (OCT) is developed for wind turbines. This transmission realizes continuous shifting by alternating power transfer between a friction clutch and an overrunning clutch. To study the shift smoothness of this automatic transmission, a six-degree-of-freedom dynamic model of a two-speed transmission was established. A coordinated control strategy for the clutch and power source during shifting was proposed, and simulation and test bench studies were conducted. The results show that the proposed upshift and downshift control strategies can effectively reduce shift impact, keeping the jerk during shifting within 10 m/s³.
... Through extensive research, a novel configuration combining a 2-bladed modified Savonius Bach-type rotor and a 3-bladed Darrieus turbine was modeled and analyzed using computational fluid dynamics (CFD) to determine characteristic parameters [39]. The generated geometry was employed in CFD Meshing for further analyses, evaluating the hybrid VAWT's overall performance. ...
Currently the domain of design and installation of Vertical Axis Wind Turbines (VAWT) is in a developing phase and contemporary researches propose various methods to develop a VAWT. This system is showing a potential solution of domestic energy need. A review of current researches is required to proceed further towards a better understanding of VAWT for small requirement. The development of a VAWT is an interdisciplinary work that involves the core knowledge of various branches of engineering. This review work aims to assess the various processes and methodologies to design and install vertical axis wind turbine for efficient energy generation in urban and small-scale settings. A thorough literature survey is done to fulfil the objective of the review. This work also holds significance as it addresses the need for innovative solutions in smart renewable energy generation. The outcomes of this study will provide guidance towards a better understanding of recent trends of development of VAWT and scope of further work to make the technology more efficient and smart.
... Through the analysis of the vibration signal, the fault range and nature of the gearbox are obtained [18,19]. ...
To ensure the healthy, safe, and stable operation in the design working life, a gear box safe operation remote monitoring model is designed based on modern sensing, computer detection, wireless communication, and big data analysis. It is of great significance to realize the early diagnosis and early warning of gearbox fault and to improve the reliability and safety of the whole wind turbine operation. First, the mechanical structure and operation characteristics of the gearbox are studied, and the failure of the mechanical mechanism is analysed. Then, based on this fault situation, a set of monitoring scheme and fault diagnosis, including mechanical vibration analysis and on-site video monitoring, is proposed. Finally, the hardware and software of the model as well as digital signal processing module are designed to collect and process the data of various sensors. ARM is responsible for data storage and data display. WEB server provides convenience for wind turbine operation and maintenance personnel to perform fault monitoring, analysis and diagnosis in real time in the background. SIM900A is responsible for remote data transmission. Through actual experiments, under the background of big data, the fault detection of wind turbine gearbox in the operation process is realized, and mechanical accidents caused by gear wear and aging are avoided to a large extent. The operation of the gear is guaranteed and the safety is improved, making it more stable and real-time. Moreover, the operation and maintenance costs of enterprises are reduced. In short, intelligent analysis of wind turbines through big data can ensure the safe operation of the gearbox, which has reference significance for the healthy progression of wind power industry.
Vertical Axis Wind Turbines (VAWTs) offer several advantages over horizontal axis wind turbines (HAWTs), including quieter operation, ease of maintenance, and simplified construction. Surprisingly, despite the prevailing belief that HAWTs outperform VAWTs as individual units, VAWTs demonstrate higher power density when arranged in clusters. This phenomenon arises from positive wake interactions downstream of VAWTs, potentially enhancing the overall wind farm performances. In contrast, wake interactions negatively impact HAWT farms, reducing their efficiency. This paper extensively reviews the potential of VAWT clusters to increase energy output and reduce wind energy costs. A precise terminology is introduced to clarify ambiguous terms researchers use to quantify cluster parameters. While examining commonly studied and proposed VAWT cluster configurations, several aspects are discussed such as aerodynamic interactions, wake characteristics, structural dynamics, and performance metrics. Additionally, the current state-of-the-art and research gaps are critically described. The review also covers computational modeling, optimization techniques, advanced control strategies, machine learning applications, economic considerations, and the influence of terrain and application locations.
Wind turbines are widely used these days as one of renewable energy sources. In this paper, a dynamic model of a vertical axis wind turbine is developed by considering coupling effects among shaft bending, shaft torsion, shaft tension, rotor tension and rotor bending. The modal characteristics of the vertical axis wind turbine were obtained by using the dynamic model. The accuracy of the proposed model was first validated by comparing its numerical results to those obtained with a commercial program. Then, the effects of key design parameters such as shaft length, shaft diameter and rotor cross section area on the modal characteristics of the wind turbine were investigated. The natural frequency loci veering phenomena occurred when those parameters varied. The loci veering phenomena were associated with the mode shape switch between shaft bending and rotor bending, which should be carefully examined to improve the vibration quality of the wind turbine. The main contribution of this study is to propose a simple vibration model by which the effects of various design parameters on the modal characteristics of the vertical axis wind turbine can be investigated. Some design guidelines related to the vibration performance are also suggested.
