Grant: Discovery Grants Program - Individual

The aviation industry is targeting net zero carbon dioxide (CO2) emissions by 2050. Aviation is challenging to decarbonize due to weight and volume constraints on aircraft. For flights lasting more than a few hours, ducted fans (as opposed to propellers) are likely to continue to be the main propulsors used. This is because they enable higher flight speeds. To reduce CO2 emissions (there will be some net emissions even with sustainable aviation fuels), significant improvements to aircraft energy efficiency are needed. Propulsion systems employing ducted fan propulsors are likely to be used in configurations which result in spatially non-uniform flows entering fans throughout the flight profile. This research program will solve critical aerodynamic design problems required to realize high-performance fans for aeronautical propulsion applications in future configurations such as boundary layer ingestion (BLI), where traditional design approaches have been shown to lead to lower than desired efficiency. This will be achieved by demonstrating the benefits of new design concepts applied to BLI fans. Specifically, the idea of altering the shapes of the blades in the stationary blade row (stator) downstream of the fan rotor to maximize efficiency will be explored in detail, and design guidelines established. Also, the shape of the "nose" of the fan, the part upstream of the blades, will be altered to reduce spatial variation in the airflow entering a BLI fan. Finally, individual stator blade setting angle variations will be explored to determine if off-design performance can be improved. These problems will be tackled with a mix of numerical simulations of air flow and experiments. This research is important to the aviation industry as a means to advance the state of the art for propulsion systems using BLI. This should lead to more environmentally sustainable solutions getting to market sooner. BLI systems are not currently in use on commercial aircraft since the lack of clear design guidelines means that the benefits might not outweigh the drawbacks. Overcoming these drawbacks will enable BLI propulsors for future commercial aircraft, which will help with reducing emissions and costs for aviation. Demonstrating the impact of innovative design practices in terms of improving efficiency will lead to an increase in the level of confidence in developing BLI aircraft and propulsors. A reasonable estimate of BLI benefit is 10% reduction in fuel burn, so based on 2022 global aviation emissions, replacing tube-and-wing aircraft with BLI designs could eliminate 80 Mt of CO2 annually, equivalent to 17.8 million average gasoline-powered cars' annual emissions. As the climate emergency is a global problem, this will benefit Canada along with the rest of the planet. In addition, the know-how from the research and instilled in trainees will benefit Canada's aerospace industry.