Effects of Particulate Contamination and Jet Fuel Chemistry on the Nucleation of Water and Ice in Aircraft Fuel Systems

The aviation industry is currently facing increasing environmental and energy challenges regarding its fuel use. Research is therefore currently under way to develop new sustainable aviation fuels. Understanding the properties of these fuels (along with the changing properties of existing fuel types) is required to understand their impact on aircraft fuel systems. Water solubility, water settling and ice formation in fuel are such properties of interest. The presence of water in jet fuel/fuel systems has been a long-standing issue in the aviation industry. Therefore, it is important to precisely identify the conditions and features that may exacerbate this phenomenon, understanding how fuel composition, temperature, water droplet sizes, flowrate and pipe surface affect ice formation and water solubility. Currently, there is relatively limited data regarding water solubility/settling rate and ice formation in sustainable fuels, specifically those specified in ASTM D7566. This work gives a comprehensive account of the recent advances and technologies in the literature indicating conditions that might lead to the nucleation of water and ice in aircraft fuel systems. These conditions have then been applied to characterizing dispersed water droplets in alternative fuels and conventional Jet A-1. Subsequently, the requirements have been applied to the design, set up, and effectiveness of an ice test rig to understand the types and amounts of ice that can be produced from different sustainable aviation fuel blends. In doing so, this work has helped shed light on the role of fuel composition in ice accretion and whether ice accumulation on a pump inlet strainer may impact pump performance. Furthermore, the results from this work will serve as a basis for design guidelines to minimise ice formation within an aircraft fuel system and help identify some potential/sustainable jet fuel candidates for ASTM D7566 certified jet fuels.Ph