Mapping the mineralogy of dust in the atmosphere to help promote sustainable aviation

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Mineral dust ingested from the atmosphere is increasingly a problem for the health of aircraft gas turbine engines, both as dust storms have become more frequent in response to the consequences of climate change, and as modern engines have become hotter in the drive to improve engine efficiency. The ingested mineral particles cause a number of different types of damage, leading to increased fuel burn and a substantial reduction in engine component life. The nature of damage is driven by the precise mineral composition, size and shape of the ingested dust particles, particularly between the ground surface and midway through climb (altitudes of 0 to ~5000 m). Therefore, it is important to understand the controls on the composition of atmospheric dusts vertically through the lower troposphere, and how the composition of airborne dust changes both across regions of differing underlying source geology and through seasonal changes in atmospheric circulation. Our present knowledge about the mineralogical composition of atmosphere dust, particularly for particles >10 micron-micrometer in size, is limited both because direct, airborne sampling is expensive and difficult, and because current sampling strategies are focussed on climate studies. This EPSRC-Rolls-Royce funded DTP study will focus on the compositional relationship between airborne mineral dust and source ground deposits, with particular focus on vertical and downwind aerodynamic particulate sorting associated with dust storm events. This project will involve substantial field work, with several months in Australia where the student will characterize mineral dust types as they are found on the ground and in the air using a combination of ground and airborne sampling techniques, including using drones and weather balloons fitted with specially adapted filter samplers. The collected samples will be analysed for particle size distribution and mineral composition using Raman, SEM, XRD and related geochemical analytical techniques. The student will undertake wind tunnel experiments to develop and test the sampling equipment, and to investigate near surface aerodynamics and mineral sorting from polymineralic dusts during mobilization from the ground to the air.