Methods and Criterion for Adaptive Ice Accretion Simulation: Mesh Boundary Merge and Reconstruction

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The strong coupling effect of two-phase flow and ice accompanies the ice accretion process of aircraft and wind turbine in damp and cold environment. A method based on the Eulerian two-phase flow, domain discretization of finite volume method (FVM) and finite element method (FEM), and fluid–solid coupling for numerical simulation of ice accretion is presented in this paper. In addition, the icing process of two-dimensional (2D) ice accretion on airfoils is investigated. It is found that the difference between simulation results and experimental data comes from the phase changes of local collection efficiency [Formula: see text], which is a function of local vortex strength and changes with time. Furthermore, with the ice accretion, it is easy to generate a negative or distortion grid because of the inappropriate mesh boundary merge and reconstruction, leading to an inaccurate ice prediction result. Based on the influence region of icing accretion and capturing the complex flow characteristics of the near-wall region, a dynamic and partition adaptive grid reconstruction strategy between macroscopic ice layer and microscopic ice crystal growth process is established. This is then used to build the ice accretion step adjustment strategy for multi-step simulation method under different icing conditions. The droplet collection efficiency distribution is modified by considering the vortex structure in the near-wall region. For verification purposes, multi-step simulation results for ice accretion of NACA0012 airfoil and large camber and strong separation airfoil under specified icing conditions are compared with the corresponding experimental data and some previously predicted results. The results of quantitative comparison of ice shape indicate that the current calculation method has better consistency with the experimental data, especially for glaze ice. The similarity of ice shape is more than 20% higher than the previous prediction results, showing that the time-space adaptive adjustment strategy has good robustness and accuracy for ice prediction.