Multilayer Modeling of Rime-Onset Transitional Icing with Unsteady Conduction and a Modified Messinger/Myers Framework

This study revisits the Myers icing model by developing a multilayer unsteady formulation that captures the full rime-to-glaze transition under realistic atmospheric and thermal conditions. Unlike models that assume direct glaze formation, our approach begins with rime ice accretion and evolves into glaze based on physically consistent transitions governed by energy and mass balances. Sublimation and evaporation at the ice–air and water–air interfaces are incorporated, and a modified Myers model is proposed to describe the transition accurately. The formulation resolves layered conduction and water film dynamics without assuming lateral runback. Simulations show that while the rime-to-glaze transition time may be short in favorable conditions, glaze ice always initiates from a rime phase. Two distinct modes of mixed-phase icing are identified: one caused by surface heat flux deficits during the transition, and another triggered by abrupt atmospheric changes. These lead to nonuniform ice structures and emphasize the importance of capturing unsteady effects in transitional icing.