Modelling of ice crystal icing in engines

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[1] The development of mathematical and computational models for the prediction of Turbofan engine deterioration is of great importance in the aerospace industry. Recently, the industry has noted that ice crystal icing (ICI) is likely responsible for numerous observed instances of power loss and engine damage. In this scenario, ice crystals present at high altitudes enter the hot engine core. Despite the high temperatures in the core, the crystals can accrete on the interior surfaces in a partially melted state, and then shed outwards, damaging key components and causing a power loss. Existing knowledge on the mechanism of ice crystal build-up and shedding is extremely limited; recent experimental work has been done to better understand the initial ice crystal impact, but accurate mathematical and computational models have not yet been developed. In particular, these latter reports have highlighted the pressing need to develop better understanding of the fundamental physics of ICI. The focus of this PhD project will be to develop mathematical models for the analysis of ice-crystal formation in the hot engine core. [2] In particular, our aim is to formulate low-dimensional discrete or continuum models that contain the essential physics of the process. The models will need to describe the processes of initial impact, attachment and accretion; and separation. These models will be studied in order to derive scaling laws for key quantities such as the accretion rates, melting rates, and separation thresholds. We will also develop theoretical (asymptotic) and computational methods for their study. Once the fundamental models have been formulated and studied, the PhD will consider significant extensions that may include some of the following: (i) generalisations to incorporate additional physics (e.g. variable flow fields and heat transfer conditions, different ice crystal densities) and complex curved geometries; (ii) verification against recent experimental results and data; (iii) the investigation of inverse problems (e.g. given engine diagnostics, can the flight conditions be determined?.