Numerical calculation for water droplet parameters change and its effect on impingement property in icing wind tunnel

Numerical simulation was conducted for the air and water droplets two-phase flow along the icing wind tunnel. The mass and heat transfer models between droplets and cold air were built by using Lagrange method. The temperature, diameter, velocity and trajectories changes along the duct for water droplets with different initiiil dinmeter were ciilculiited∗ the influences of the velocity and diameter changes on the implement property were studied and four different Lee-dimensional distributions of local collection coefficient along the wingspan were calculated under 4 different kinds of nozzles arrangements. The results showed that the water droplet temperature has a good following of the airflow; evaporation effect on smaller droplets is heavier than that on larger droplets; the trajectory of small droplet almost coincides with the air streamline, while large droplet deviates greatly from air streamline; the distribution of small water droplets in the test section can be controlled by activating different height nozzles, while large droplets are concentrated at the center of fhe test section; the change of the velocity will lead to an increase in the local collection coefficient, while the change of diameter will lead to a slight decrease in the collection coefficient; the distance between adjacent nozzles has a decisive influence on the uniformity of the icing cloud in the test section, and the smaller the distance is, the more uniform the idng cloud distribution is. The uniformity of icing cloud can only be improved slightly when the distribution of nozzles are changed from aligned arrangement to staggered arrangement in the certain numbers of nozzles.