Grant: Alliance Grants

Although there is an on-going shift towards the electrification of transport, gas turbines will remain relevant to future energy production due to their unrivaled power-density, reliability and efficiency. In light of the on-going climate change crisis and the importance of gas turbines in the future energy mix, it is imperative to continue improving the efficiency and reducing the emissions of gas turbines, notably by the use of carbon-neutral fuels such as biofuels, electrofuels, or hydrogen, amongst others. The use of such fuels leads to challenges due to their different combustion characteristics, and as such require the design of new combustion systems to be used efficiently. Additive manufacturing (AM) can improve the performance of such combustion systems by allowing complex flow paths to be manufactured quickly and cheaply with high-performance superalloys. However, one issue often overlooked with additive manufacturing is the high surface roughness of the parts produced, which is known to affect the formation of carbon deposits (i.e., coking) when used in fuel systems. By allowing complex internal passages, additive manufacturing can mitigate this issue by providing enhanced cooling capabilities, but developing an understanding of coking behavior with additive manufacturing is necessary in order to achieve reliable fuel-flexible gas turbines. The available literature shows that high roughness due to additive manufacturing does indeed increase coking, but provides no clear design guidelines to address this issue. This research will seek to experimentally assess the effects of additive manufacturing on coking of fuel injectors, thus directly filling a knowledge gap by developing new design guidelines for AM fuel injectors to avoid coking.