Research On The Interference In Vertical Axis Tidal Turbine Array Based On OpenFOAM

With the fossil energy is facing a more and more severe situation of shortage,clean and pollution-free tidal current energy is gradually being widely concerned around the world.As the main energy capture device of tidal current energy,vertical axis tidal turbine is favored by researchers for its simple structure,low manufacturing cost and high efficiency.Due to the construction and maintenance cost constraints of turbine in the tidal current power station,the application of a single turbine has not much significance,and the station has large scale of turbine array could demonstrate the economic value of tidal current utilization better.Therefore to study the interference effect of turbine array and arrange the turbines reasonable in the limited tidal current field are important problems involved in large-scale tidal current power generation.At first the mechanical characteristics and working principle of vertical axis turbine are introduced in this paper,and by comparing with the experimental data found that the two-dimensional numerical simulation method based on open source CFD software OpenFOAM for vertical axis turbine with accuracy and feasibility.Then,based on this numerical simulation method single vertical axis turbine is researched,obtained the change law of the turbine's efficiency and mechanical characteristics,the influence of velocity inlet's turbulence intensity to the turbine's power efficiency is also analyzed.Later,the interference effect of three forms of tandem,parallel and staggered twin-turbine array are studied systematically,the influence of the factors such as turbine spacing,rotation direction and initial position angles difference on the hydrodynamic performance of twin-turbine array is analyzed emphatically.Achieved the conclusion of the optimal arrangement scheme of twin-turbine array is parallel outer counter rotating form.Meanwhile,the smaller lateral distance between outer counter rotating turbines is beneficial to the output of power,but the small spacing will make the installation of blades and the daily maintenance of the turbines difficult.Moreover the force fluctuation amplitude of turbine carrier can be reduced by reasonable selection of the initial position angles difference of turbines.Finally,a symmetric simplified model is introduced to study the single-row and double-row arranged vertical axis turbine array,the turbines' mechanical characteristics and turbine array wake characteristics are analyzed in detail by the comparison of different layout scheme.The study found that the different rotation direction form of the single-row turbine array is favorable in terms of obtain energy,the array optimization solution provided the design basis for large scale multi-row layout of vertical axis tidal turbines.Through the systematic study of vertical axis tidal turbine array,the interference mechanism,interference forms and interference results between turbines are revealed.The power generation capacity and force characteristics of the turbines are considered during the study process.From the view of hydrodynamics,the vertical axis tidal turbine array arrangement scheme and the basic principle for the practical distribution are put forwarded,which provides a theoretical basis for the actual distribution of turbines in tidal current power station,and has certain guiding significance to the commercialization and large-scale popularization of tidal current energy development.