Experimental Study On Hydrodynamic Model Of Vertical Axis Turbine In Bounded Water

The reserves of non renewable energy,such as coal,oil and natural gas,are decreasing with continuous exploitation and utilization.However,the demand for energy is increasing with the development of industrial production and the growth in the living standard.The traditional energy has been unable to meet the needs of human being,and the development of renewable energy has now become an inevitable trend of the world’s energy development.The total amount of renewable energy in the ocean is rich,and it is the treasure house of the future energy of human being.The vertical axis water turbine is a kind of device which can convert the tidal power into the electric energy in this paper.This experiment is based on the 2013 ocean renewable energy special fund—the ocean energy comprehensive support service platform construction project,having indoor fixed test research for tidal current fixed angle vertical axis turbine.The purpose of the experiment is to establish the vertical axis turbine test platform,determine the hydrodynamic performance and load testing method of the vertical axis turbine,studying on the influence of main parameters including the flow velocity,speed radio,the blade chord size for the hydrodynamic performance and load performance of the turbine.The experimental results are numerically processed by using the filtering method and other methods.Through the study of the experimental results,it is found that:(1)The spokes and clamps of the impeller reduce the energy utilization ratio and increase the load performance of the turbine,the size of the fixture has great influence on the hydrodynamic performance of the turbine.(2)There is an optimal speed ratio for the turbine,and the power coefficient is the greatest under the speed ratio.(3)Under the same speed ratio,the higher the flow velocity,the lower the average power coefficient.And the greater the speed ratio,the greater the power coefficient is affected by the flow velocity.The larger the flow velocity,the smaller the average thrust coefficient and the greater the average lateral force coefficient.(4)The chord size also has a significant effect on the hydrodynamic performance and load performance.At low speed ratio,increasing the blade chord can inhance the utilization rate of turbine energy.At high speed ratio,reducing the energy utilization rate can raise the blade chord.The hydraulic turbine is simulated by CFD software CFX,and the influence of the free surface,the spokes and the wall effect on the hydrodynamic performance of the hydraulic turbine is studied.The experimental results are compared with the CFD results,and the differences and reasons of the two results are analyzed.The results of this study provide experimental data for the design,installation and CFD validation of vertical axis turbine impeller and have guiding significance for design and construction of hydraulic turbine in real conditions,promoting the progress of experimental study on the vertical axis of water turbine and having great significance on energy conversion device study of tidal power.