Model for aircraft icing with consideration of property-variable rime ice

A new one-dimensional model has been developed to describe the aircraft icing process based on the fundamental theory of solid-liquid phase change. The model assumes that there exist two modes for aircraft icing, i.e. the dry and the wet mode icing. Rime ice forms on aircraft skin during the dry mode icing, which occurs at the early icing stage, with its physical properties being affected by airflow parameters and varying with the ice thickness. Glaze ice forms on the rime ice when water film appears on the glaze ice during the wet mode icing, which takes place at the later icing stage. The uniqueness of the model is to consider the rime ice as a porous medium and assume that its effective properties are initially determined by the airflow parameters and then vary linearly with the rime ice thickness, with the properties continuing at the rime/glaze ice interface. Calculations are conducted to analyze the ice accretion characteristics, and the results are presented with comparison with those given by some classical icing models. The results suggest that the ice accretion process is affected by the airflow parameters as well as the heat conductions in the ice layer and water film, and the model with consideration of property-variable rime ice can better describe the ice accretion process.