Structural Dynamic Analysis of a Tidal Current Turbine Using Geometrically Exact Beam Theory

Author(s):  
Qi Wang ◽  
Pengkun Zhang ◽  
Ye Li

This paper presents a numerical study of the dynamic performance of a vertical axis tidal current turbine. First, we introduce the geometrically exact beam theory along with its numerical implementation the geometric exact beam theory (GEBT), which are used for structural modeling. We also briefly review the variational-asymptotic beam sectional analysis (VABS) theory and discrete vortex method with free-wake structure (DVM-UBC), which provide the one-dimensional (1D) constitutive model for the beam structures and the hydrodynamic forces, respectively. Then, we validate the current model with results obtained by ANSYS using three-dimensional (3D) solid elements and good agreements are observed. We investigate the dynamic performance of the tidal current turbine including modal behavior and transient dynamic performance under hydrodynamic loads. Finally, based on the results in the global dynamic analysis, we study the local stress distributions at the joint between blade and arm by VABS. It is concluded that the proposed analysis method is accurate and efficient for tidal current turbine and has a potential for future applications to those made of composite materials.

Author(s):  
Jun Leng ◽  
Ye Li

In recent years, tidal current energy has gained wide attention for its abundant resource and environmentally friendly production. This study focuses on analyzing dynamic behavior of a three-bladed vertical axis tidal current turbine. The multibody dynamics code MBDyn is used in the numerical simulation. It performs the integrated simulation and analysis of nonlinear mechanical, aeroelastic, hydraulic and control problems by numerical integration. In this study, tidal current turbine is idealized as an assembly of flexible beams including axis of rotation, arms and blades. We firstly conduct a modal analysis on the tidal current turbine and validate the model with the results obtained by ANSYS. The natural frequencies of blades with different size parameters are compared and the corresponding mode shapes are presented. Next, a parametric study was performed to investigate the effect of internal force on the dynamic response. It is concluded that the proposed method is accurate and efficient for structural analysis of tidal current turbine and this flexible multibody model can be used in the fluid-structure-interaction analysis in the future.


Author(s):  
Ye Li ◽  
Sander M. Calisal

Tidal power technology has been dwarfed once to take hold in the late 1970’s, because the early generations were expensive at small scale and some applications (such as barrages) had negative environmental impacts. In a similar working manner as a wind turbine, a tidal current turbine has been recognized as a promising ocean energy conversion device in the past two decades. However, the industrialization process is still slow. One of the important reasons is lack of comprehensive turbine hydrodynamics analysis which can not only predict turbine power but also assess impacts on the surrounding areas. Although a lot can be learned from the marine propeller or the wind turbine studies, a systematic hydrodynamics analysis on a vertical axis tidal current turbine has not been reported yet. In this paper, we employed vortex method to calculate the performance of stand-alone vertical axis tidal turbine in term of power efficiency, torque and forces. This method focuses on power prediction, hydrodynamics analysis and design, which can provide information for turbines distribution planning in a turbine farm and other related studies, which are presented in Li and Calisal (2007), a companion paper in the conference. In this method, discrete vortex method is the core for numerical calculation. Free vortex wake structure, nascent vortex and vortex decay mechanism are discussed in detail. Good agreements in turbine efficiency comparison are obtained with both the newly-designed tidal turbine test in a towing tank and early wind turbine test.


Author(s):  
Ye Li ◽  
Sander M. Çalışal

This paper advanced our recent effort (Li and Çalışal, 2007, “Preliminary Result of a Discrete Vortex Method for Individual Marine Current Turbine,” The 26th ASME International Conference on Offshore Mechanics and Arctic Engineering, Jun. 10–15, San Diego, CA) to study the behavior of tidal-current turbines. We propose a discrete-vortex method with free-wake structure (DVM-UBC) to describe the behavior of a stand-alone tidal-current turbine and its surrounding unsteady flow and develop a numerical model to predict the performance and wake structure of the turbine based on DVM-UBC. To validate this method, we conducted a series of towing tank tests. DVM-UBC is then validated with several kinematic and dynamic results. When we compared the results obtained with DVM-UBC with our towing tank test results, published results, and the results obtained with other numerical methods, we achieved good agreements. Our comparisons also suggested that DVM-UBC can predict the performance of a turbine 50% more accurately than the traditional discrete-vortex method (traditional DVM) with comparable computational effort and will produce results comparable to the Reynolds averaged Navier–Stokes equation with much less computational effort.


2020 ◽  
Vol 10 (4) ◽  
pp. 1231 ◽  
Author(s):  
Zhipei Wu ◽  
Jili Rong ◽  
Cheng Liu ◽  
Zhichao Liu ◽  
Wenjing Shi ◽  
...  

With increasing of the size of spatial truss structures, the beam component will be subjected to the overall motion with large deformation. Based on the local frame approach and the geometrically exact beam theory, a beam finite element, which can effectively reduce the rotational nonlinearity and is appropriate for finite motion and deformation issues, is developed. Dynamic equations are derived in the Lie group framework. To obtain the symmetric Jacobian matrix of internal forces, the linearization operation is conducted based on the previously converged configuration. The iteration matrix corresponding to the rotational parameters, including the Jacobian matrix of inertial and internal forces in the initial configuration, can be maintained in the simulation, which drastically improves the computational efficiency. Based on the Lagrangian multiplier method, the constraint equation and its Jacobian matrix of sliding joint are derived. Furthermore, the isogeometric analysis (IGA) based on the non-uniform rational B-splines (NURBS) basis functions, is adopted to interpolate the displacement and rotation fields separately. Finally, three dynamic numerical examples including a deployment dynamic analysis of spatial truss structure are conducted to verify the availability and the applicability of the proposed formulation.


2015 ◽  
pp. 601-612
Author(s):  
B Morandi ◽  
F Di Felice ◽  
M Costanzo ◽  
G Romano ◽  
D Dhomé ◽  
...  

2018 ◽  
Vol 198 ◽  
pp. 04004
Author(s):  
P. T. Ghazvinei ◽  
H.H. Darvishi ◽  
A. Bhatia

Marine current power is a significant energy resource which is yet to be exploited for efficient energy production. Malaysia, being a tropical country is rich in renewable sources and tidal power is one of them. In Malaysia, Straits of Malacca is a potential site to establish a tidal current turbine. In the current study, the potential sites of the Straits of Malacca are discussed. A detailed review about the generator suitable for the Straits of Malacca with the associated challenges has also been discussed. Furthermore, the suitable solution for such challenges is proposed. The role of simulation in choosing an appropriate site and generator has also been reviewed. The focus of the study is to propose a generator suitable for the flow characteristics of the Straits of Malacca.


2020 ◽  
Vol 264 ◽  
pp. 114621 ◽  
Author(s):  
Guizhong Deng ◽  
Zhaoru Zhang ◽  
Ye Li ◽  
Hailong Liu ◽  
Wentao Xu ◽  
...  

2020 ◽  
Vol 210 ◽  
pp. 107320 ◽  
Author(s):  
Wang Hua-Ming ◽  
Qu Xiao-Kun ◽  
Chen Lin ◽  
Tu Lu-Qiong ◽  
Wu Qiao-Rui

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