Dynamic characteristics investigation of the fuel supply system for liquid hydrogen aero-engines

Abstract

Hydrogen fuel, due to its high gravimetric energy density and carbon-free combustion products, has been widely regarded as one of the most promising alternative fuels for enabling significant decarbonization in the aviation sector. The dynamic response characteristics of the liquid hydrogen fuel supply system play a crucial role in evaluating the transient performance and ensuring the operational safety of hydrogen-fueled aero-engines. In this study, a dynamic simulation model of a liquid hydrogen fuel supply system was developed, which integrates a heat exchanger model, a one-dimensional unsteady compressible flow model for the hydrogen supply pipeline, and a fuel nozzle model. The response behaviours of system pressure, flow rate, and temperature were analysed under varying liquid hydrogen flow rates and pipeline pressures. Simulation results demonstrate that during step changes in the liquid hydrogen flow rate (increases of 10% and 30%), the response lag times for flow rate, pressure, and temperature at the nozzle were observed to fall within the range of approximately 0.52 s to 0.72 s. Moreover, a small-amplitude step disturbance is sufficient to capture the dynamic behaviour of the system. The pipeline’s design pressure was identified as a key factor affecting the response lag at the nozzle. As the pipeline design pressure increases from 1.6 MPa to 6.0 MPa, the lag times for flow rate, pressure, and temperature at the nozzle are observed to increase by approximately 3 to 5 times.