エンジンファン着氷における氷の離脱現象のモデル化

抄録

In a jet engine, icing phenomena may occur primarily on the fan blades, the fan exit guide vanes (FEGVs), the splitter, and the low-pressure compressor. Accreted ice disturbs the inlet flow and causes large energy losses. In addition, ice accreted on a fan rotor can be shed from the blade surface due to centrifugal force and can damage the compressor components. This phenomenon, which is typical in turbomachinery, is referred to as ice shedding. The ice shedding phenomenon is very complicated because there are several unknown physical properties of ice, such as the ice density, the adhesion force between accreted ice and the wall, and the contact force between ice pieces. Moreover, although existing icing models can simulate ice growth, these models do not have the capability to reproduce ice shedding. In the present study, we developed an icing model that takes into account both ice growth and ice shedding. We validated the proposed ice shedding model through the comparison of numerical results and experimental data, which includes the flow rate loss due to ice growth and the flow rate recovery due to ice shedding. The predictive shedding time obtained using the proposed ice shedding model were in good agreement with the experimental data. Finally, we investigated the effects of ice growth and ice shedding on the fan performance.