Performance Of Tidal Current Turbine Research Articles

Numerical investigation of modal and fatigue performance of a horizontal axis tidal current turbine using fluid–structure interaction

The tidal power has the potential to play a vital role in a sustainable energy future. The main objective of this paper is to investigate the performance and fatigue life of tidal current turbine (TCT) using fluid structure interaction (FSI) modeling. The performance of TCT was predicted using Ansys CFX. The performance curve, pressure distribution on the blade, and velocity streamline were visualized for eight repetitive analyses at different tip speed ratio. The hydrodynamic load calculated from CFD analysis was transferred to FEA model for investigation of the structural response of TCT. Modal analysis was performed to examine the mode shapes and natural frequencies of TCT. The fatigue analysis were performed and number of cycles and safety factor at different equivalent alternating stresses were investigated. The results of the simulation confirm that the turbine has a maximum value of the coefficient of performance at λ = 5, the turbine operating frequency is not close to its natural frequency, and it is safe under the applied fatigue loads with a high factor of safety.

Numerical and Experimental Investigations on the Hydrodynamic Performance of a Tidal Current Turbine

In this paper, numerical and experimental investigations are presented on the hydrodynamic performance of a horizontal tidal current turbine (TCT) designed and made by our Dalian University of Technology (DUT) research group. Thus it is given the acronym: DUTTCT. An open source CFD solver, called PimpleDyMFoam, is employed to perform numerical simulations for design analysis, while experimental tests are conducted in a DUT towing tank. The important factors, including self-starting velocity, tip speed ratio (TSR) and yaw angle, which play important roles in the turbine output power, are studied in the investigations. Results obtained show that the maximum power efficiency of the newly developed turbine (DUTTCT) could reach up to 47.6% and all its power efficiency is over 40% in the TSR range from 3.5 to 6; the self-starting velocity of DUTTCT is about 0.745m/s; the yaw angle has negligible influence on its efficiency as it is less than 10°.

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

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.

Numerical and Experimental Investigations on the Hydrodynamic Performance of a Tidal Current Turbine

In this paper, numerical and experimental investigations are presented on the hydrodynamic performance of a horizontal tidal current turbine (TCT) designed and made by our Dalian University of Technology (DUT) research group. Thus, it is given the acronym: DUTTCT. An open-source computational fluid dynamics (CFD) solver, called pimpledymfoam, is employed to perform numerical simulations for design analysis, while experimental tests are conducted in a DUT towing tank. The important factors, including self-starting velocity, tip speed ratio (TSR), and yaw angle, which play important roles in the turbine output power, are studied in the investigations. Results obtained show that the maximum power efficiency of the newly developed turbine (DUTTCT) could reach up to 47.6%, and all its power efficiency is over 40% in the TSR range from 3.5 to 6; the self-starting velocity of DUTTCT is about 0.745 m/s; and the yaw angle has negligible influence on its efficiency as it is less than 10 deg.

The prediction of the hydrodynamic performance of tidal current turbines

Nowadays tidal current energy is considered to be one of the most promising alternative green energy resources and tidal current turbines are used for power generation. Prediction of the open water performance around tidal turbines is important for the reason that it can give some advice on installation and array of tidal current turbines. This paper presents numerical computations of tidal current turbines by using a numerical model which is constructed to simulate an isolated turbine. This paper aims at studying the installation of marine current turbine of which the hydro-environmental impacts influence by means of numerical simulation. Such impacts include free-stream velocity magnitude, seabed and inflow direction of velocity. The results of the open water performance prediction show that the power output and efficiency of marine current turbine varies from different marine environments. The velocity distribution should be clearly and the suitable unit installation depth and direction be clearly chosen, which can ensure the most effective strategy for energy capture before installing the marine current turbine. The findings of this paper are expected to be beneficial in developing tidal current turbines and array in the future.

New Concept for Assessment of Tidal Current Energy in Jiangsu Coast, China

Tidal current energy has attracted more and more attentions of coastal engineers in recent years, mainly due to its advantages of low environmental impact, long-term predictability, and large energy potential. In this study, a two-dimensional hydrodynamic model is applied to predict the distribution of mean density of tidal current energy and to determine a suitable site for energy exploitation in Jiangsu Coast. The simulation results including water elevation and tidal current (speed and direction) were validated with measured data, showing a reasonable agreement. Then, the model was used to evaluate the distribution of mean density of tidal current energy during springtide and neap tide in Jiangsu Coast. Considering the discontinuous performance of tidal current turbine, a new concept for assessing tidal current energy is introduced with three parameters: total operating time, dispersion of operating time, and mean operating time of tidal current turbine. The operating efficiency of tidal current turbine at three locations around radial submarine sand ridges was taken as examples for comparison, determining suitable sites for development of tidal current farm.

Modelling tidal current turbine wakes using a coupled RANS-BEMT approach as a tool for analysing power capture of arrays of turbines

An improved method is developed to couple an inner domain solution of the blade element momentum theory with an outer domain solution of the Reynolds averaged Navier Stokes equations for evaluating performance of tidal current turbines. A mesh sensitivity study shows that a mesh of at least 6 M cells with at least 40% of these within the turbine wake is required to ensure satisfactory convergence of the velocity deficit. In addition to the usually applied axial momentum source terms, angular momentum and turbulence intensity source terms are shown to be required to model the near wake evolution. Three different lateral turbine spacing of 2, 4 and 6 turbine diameters are used to demonstrate the influence of the effective channel blockage on the velocity distribution in the turbine bypass region, the rate of spread of the wake and the recovery of velocity distribution. A final study shows that for a fixed number of turbines minimising the lateral spacing within each row, with a small number of staggered rows spaced as longitudinally as far apart as practical, is the most effective strategy for energy capture.