In order to ensure the flight safety, ground icing tests, including aero-engine entry components tests, must be done during the R&D process of a new machine type. Most of these tests are taken in icing tunnels, which consist of usual wind tunnels and spray systems, and can be used to simulate the movement of super cooled water droplets in air. Generally, diameters of the droplets produced by the system are not unique in each test, and temperature of the water at the position of injections is much higher than the air at the same position. These factors may affect the droplets impingement characteristics and cause heat and mass transfer between droplets and the free steam. So they should be taken into account in test analysis.
In this paper, an improved Lagrangian approach is presented to simulate the unsteady process of droplets movement in the icing tunnel. This method considers the droplet size distribution where they are injected and heat and mass transfer during their movements. In addition, statistical approach is also developed in this method so that local collection coefficient of complex three-dimensional surface can be calculated. An entry strut of a turbo-shaft engine is chosen as a case to validate the effectiveness of the method. By compared with the results of experiment and former calculation, it shows that the improved method in this paper is more accurate to simulate the water droplets impingement characteristics in icing test facilities and droplets’ temperatures decrease quickly during their movements in test processes.
