Abstract:

A major difficulty in the prediction of aircraft icing is to calculate the three-dimensional ice shape on the surface of an aircraft. The main purpose of this article is to establish a numerical method for calculating the three-dimensional ice accretion. Based on the classic icing model proposed by Messinger, a three-dimensional model is presented in the article which takes into consideration the effect of runback water. Then the method of deciding the flowing direction and flux of the runback water on the surface cell is given, and an iterative algorithm for solving the model is developed. Ice accretion on an MS-317 swept wing is calculated, and the consequent ice shape is compared with that of an experiment and Lewice3D. The results show that the convergence of this method and arithmetic is good, and both rime and glaze ice shape agree well with the results of Lewice3D. For rime ice and short time glaze ice, the computational results are in good agreement with experimental data; for long time glaze ice, there are some discrepencies between the computational and experimental shape. However, the overall growth patterns and size of ice is reproduced well. The glaze ice shape of a non-swept wing is also compared with that of a swept wing, which shows that the three-dimensional effect of runback water caused by the swept wing affects icing significantly. Therefore, further verification is necessary in trying to represent the ice on a three-dimensional body by the ice on two-dimensional cross-sections of the body.

Key words: aircraft icing, three-dimensional ice accretion model, runback water, droplet collection efficiency, Eulerian method, numerical simulation