Objective   This paper aims to study the effects of the freezing phenomenon of supercooled water droplets in intake air on the aerodynamic performance of a marine power intake system under cold marine environment conditions.

  Methods  First, an NACA 0012 airfoil is taken as the research object, its aerodynamic performance is numerically simulated and the validation of the established model and numerical simulation method are verified through comparison with the experimental results. Commercial software Fluent is then further developed using the user-defined function (UDF), the numerical simulation of the impingement characteristics of supercooled water droplets is carried out based on the Lagrange method, and the water collection coefficients corresponding to various inflow conditions are obtained. Finally, combined with dynamic mesh technology and the user-defined function, the icing characteristics of the airfoil and its aerodynamic performance degradation characteristics after icing are numerically studied.

  Results  The results show that the intake flow angle and diameter of water droplets have a significant influence on the impingement range of the droplets and the water collection coefficient, while incoming velocity has little effect on the impingement range of the droplets, but a certain influence on the water collection coefficient. In addition, under the condition of zero degree angle of attack, the ice accretion on the leading edge of the airfoil has little effect on its aerodynamic performance. Conversely, under the condition of five degrees angle of attack, the icing of the leading edge has a serious impact on its aerodynamic performance.

  Conclusion  The results of this study can provide valuable references for the prediction and analysis of icing in marine power intake systems and subsequent anti-icing work.