To understand the phase transition effects of the droplet in an icing wind tunnel, a method based on the Euler theory is developed to simulate mass and heat transfer of coupling of momentum of gas-droplet mixed flows. Using this method, the droplet phase transition effects on the process of the droplet heat transfer are explored for the main test section configuration of a 3 m×2 m icing wind tunnel. Parametric studies are then conducted to evaluate the supercooling state of the droplet in the test section. Results show that the droplets experience firstly evaporation and then condensation in the configuration. The evaporation effects enhance the trend of decrease in the droplet temperature in the quasi-1D stage, and then make the droplet temperature close to the wet-bulb temperature. However, the condensation effects inhibit the trend of decrease in the droplet temperature in the 3D contraction stage, so that the temperature difference between droplet and gas in the test section is increased. As a result, the droplet phase transition has an effect on the supercooling state of the droplet in the test section. In addition, the increased initial relative humidity and test section velocity reduce the evaporation effects, but enhance the condensation effects. Therefore, the effects of relative humidity and test section velocity on the supercooling state of the droplet are enhanced. On the contrary, effects of both evaporation and condensation are reduced, as the initial sizes of the droplet increases. Therefore, the effect of the droplet size on the droplet supercooling is reduced. In typical test conditions, small droplets (the diameter is bigger than 40 μm and smaller than 100 μm) in the center of the test section deviate from the supercooling state (the temperature difference between droplet and gas is higher than 3℃) at the high velocity (the velocity is higher than 164 m/s).
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