3-D numerical simulation of droplet collection efficiency in large-scale wind turbine icing

A kind of three dimension numerical method , which is suitable to calculate the droplet collection efficiency in the process of large-scale wind turbine icing, is presented. The flowfield of air is computed by Multiple Reference Frame (MRF) method. Based on the distribution of air flowfield, the governing equations of water phase are solved, and then the droplet collection efficiency is obtained. Both governing equations of gas and water phase are written in the form of typical transport equations, and are solved with the same finite volume method, which makes the compile of numerical codes easier. The droplet collection efficiency on a 1.5MW horizontal axis wind turbine is computed, and the impingement characteristics of different diameter droplets are obtained, so as the distribution of droplet collection efficiency on blades are acquived. The results show that droplet collection coefficient on the hub is so little that ice on the hub can be ignored. Most water droplets impact on the leading edge of blades, and the collection efficiency on blade tip is much higher than that on blade root.