Session: 01-06 Alternative Fuels in Whole Engine Performance

Paper Number: 152936

Impact of Fuel Conditioning and Combustor Injection Temperature on a Hydrogen Turboprop 

Reduction of aviation emissions demands revolutionary propulsive technologies. Gaseous hydrogen combustion offers high potential in this regard. Some challenges arise from the use of this fuel in aero engines such as the need for a more complex fuel conditioning system. Liquid hydrogen stored in aircraft tanks needs to be brought to an adequate operating temperature for injection in the combustor through phase transformations and temperature rises. Recuperation and use of heat generated by the gas turbine could contribute to conditioning the fuel, without hindering engine performance. This article investigates the effect of the combustor injection temperature of gaseous hydrogen on the performance of a turboprop engine. Multi-point design and off-design modelling of the advanced hydrogen cycle enables identification of critical conditions in different phases of flight. Various control strategies are implemented to assess the trade-off between engine specific fuel consumption, weight and complexity of the fuel conditioning system. The results show that a reduction in fuel injection temperature is required at higher fuel flows to preserve overall aircraft performance. Low temperature values can lead to icing of the water that might be present in humid air in the burner. Additionally, lower injection temperatures lead to a reduction in the velocity of fuel injection of gaseous hydrogen. Therefore, there is a need to define a range of feasible fuel injection velocities, where the lower limit is bound by the risk of flashback in the combustor. An additional constraint to the acceptable value in fuel injection velocity is fuel rate compliance in all phases of flight. Finally, the results of a mass and fuel burn analysis define optimum sizing strategies of the fuel conditioning system for future hydrogen aircraft.

Presenting Author: Diana San Benito Pastor Safran SA

Presenting Author Biography: Dr Diana SAN BENITO:
After earning her Bachelor of Science in Aeronautical Engineering from the Universidad Carlos III de Madrid, Spain, Diana continued her academic journey at Cranfield University. There, she pursued a Master of Science in Thermal Power, followed by a Doctorate in Aerospace Propulsion, with a focus on Open Rotor technology. Upon completing her PhD, Diana advanced her career by joining the research centre at Safran in Paris, where she is currently employed as a research engineer specializing in aero engine performance. Beyond her engineering pursuits, Diana champions diversity in aerospace as ISABE's Young Professional Representative, advocating for a broader, more varied talent pool in the industry.

Authors:

Diana San Benito Pastor Safran SA
Nicolas Parmentier Safran Power Units