Research On Wind Field Characteristics And Wind Turbine Selection And Layout Optimization In Railway Tunnels

The slipstream generated by a train traveling through a tunnel can be enhanced due to spatial constraints,and its characteristics are coupled with the complex train-tunnel aerodynamic system.In the context of China’s expanding railways and continuous optimization of energy structure,exploring the selection and layout of wind turbines in the tunnel from the perspective of wind energy so as to achieve the regeneration of wind energy,is a novel initiative to further develop the green advantages of railways.In this study,a coupled aerodynamic numerical method for the train-tunnel-wind turbine system was proposed and used to investigate the wind field characteristics inside railway tunnels.Through an adaptability analysis of different types of wind turbine,the present study confirmed the wind turbine type that best matches the transient flow field inside the tunnel and performed a parameter optimization;Based on the vorticity field,a reduced-order wake model for vertical axis wind turbine was constructed,and a self-adaptive layout optimization method for wind turbines in railway tunnels was then proposed.Finally,the benefits of deploying wind turbines in railway tunnels in China were evaluated.The present study aligns with the principles of sustainable development,complies with the innovation plan of railway technology,and empowers the positive transformation of China’s energy structure,which can help China achieve the goal of “carbon peak and carbon neutrality” faster and better.(1)The slipstream formation law and wind field distribution characteristics in railway tunnels were explored.By using the dynamic fluid body interaction and overset mesh technologies,a numerical method for the train-tunnel-wind turbine coupled aerodynamics system was proposed and validated by experimental tests.Numerical method was employed to reveal the formation and evolution of the slipstream in the tunnel space,the spatial distribution characteristics of the wind field in the train-tunnel coupled aerodynamic system were also analyzed.The effects of key parameters such as train length,train speed,tunnel length,and tunnel cross-sectional area on the distribution of wind field inside the tunnel were obtained.(2)A vertical axis wind turbine design scheme that best matches the wind field characteristics in the tunnel was proposed.Targeting the wind field characteristics inside railway tunnels,a comprehensive evaluation mechanism was established,which includes indicators such as singlemachine performance,array performance,and motion intensity,the Banki turbine was then determined to be the wind turbine type that best matched the wind field characteristics in the tunnel.Parameter analysis was conducted on the geometric structure of the wind turbine and its installation position on the tunnel cross-section.The optimal design of the wind turbine was confirmed with the goal of single-machine performance,and a 60.7% increase in average power from a single wind turbine was obtained.(3)A reduced-order vertical axis wind turbine wake model based on vorticity field characteristics was constructed.A semi-empirical Jensen wake model with nested cosine function correction was proposed to address the asymmetric characteristics and attenuation pattern of the wake.From high-resolution numerical results,a reduced-order vertical axis wind turbine wake model based on the time-averaged vorticity field was developed and characterized by 27 parameters,enabling rapid and accurate estimation of wake velocity fields and suitable for analyzing and optimizing various scenarios involving multiple vertical axis wind turbines.(4)Based on the proposed self-adaptive layout optimization method of wind turbines in railway tunnels,the benefits of deploying wind turbines in railway tunnels in China were evaluated.In response to the strong and transient wind field in railway tunnels,a power estimation method for wind turbines inside the tunnels was proposed.Based on the wake model and wake mixing effect,a coupled power model for multiple vertical axis wind turbines inside railway tunnels was then constructed.Furthermore,a gridfree self-adaptive layout optimization method for wind turbine clusters inside railway tunnels was proposed.According to the optimization results and railway industry data,the deployment of wind turbines inside railway tunnels is expected to obtain 16.45 million k Wh of electricity annually,generate economic benefits and reduce 130 million tons of carbon dioxide emissions each year,making it a powerful measure to assist China in achieving “carbon peak and carbon neutrality” goal.There are 135 Figures,20 Tables,225 References.