Accurate prediction of droplet impingement on wind turbine blade is one of the most important premises of anti-icing and de-icing system design.In a super-cooled large droplets(SLD)conditions,droplet no longer maintai...Accurate prediction of droplet impingement on wind turbine blade is one of the most important premises of anti-icing and de-icing system design.In a super-cooled large droplets(SLD)conditions,droplet no longer maintains a sphere shape,and it may deform,break up,and splash when moving or impinging on the surface.Semi-empirical models of droplet dynamic behaviours are embedded into the Eulerian droplet model to improve the accuracy of the numerical simulation of droplet impingement limits and local collection efficiency.Eulerian droplet model(Model 1)for small droplets and improved Eulerian droplet model(Model 2)for large droplet are both validated by comparing to the wind tunnel experiment results.Using the proposed methods,droplet impingement limitation and local collection efficiency on the S809 airfoil are calculated in various conditions.A detailed derivation of Model 1and Model 2is presented along with a comparison of numerical trajectories,drag coefficient and collection efficiency distributions.The results show that droplet dynamic behaviours,including splashing,break-up and deforming,must be considered to accurately simulate the impingement behaviour in the SLD conditions.And with the increase of the droplet diameters,the effects of the droplet dynamic behaviors on the impingement characteristics are more obvious.展开更多
基金supported by the National Basic Research Program of China(″973″Program)(No.2014CB046200)the National Natural Science Foundation of China(Nos.11402114,51506089)+1 种基金the Fundamental Research Funds for Central UniversitiesNanjing University of Aeronautics,and Astronautics Basic Scientific Research Projects for Youth Science(No.NS2014014)
文摘Accurate prediction of droplet impingement on wind turbine blade is one of the most important premises of anti-icing and de-icing system design.In a super-cooled large droplets(SLD)conditions,droplet no longer maintains a sphere shape,and it may deform,break up,and splash when moving or impinging on the surface.Semi-empirical models of droplet dynamic behaviours are embedded into the Eulerian droplet model to improve the accuracy of the numerical simulation of droplet impingement limits and local collection efficiency.Eulerian droplet model(Model 1)for small droplets and improved Eulerian droplet model(Model 2)for large droplet are both validated by comparing to the wind tunnel experiment results.Using the proposed methods,droplet impingement limitation and local collection efficiency on the S809 airfoil are calculated in various conditions.A detailed derivation of Model 1and Model 2is presented along with a comparison of numerical trajectories,drag coefficient and collection efficiency distributions.The results show that droplet dynamic behaviours,including splashing,break-up and deforming,must be considered to accurately simulate the impingement behaviour in the SLD conditions.And with the increase of the droplet diameters,the effects of the droplet dynamic behaviors on the impingement characteristics are more obvious.
