Extending the flight endurance of stratospheric airships using regenerative fuel cells-assisted pressure maintenance

This study presents a comprehensive analysis of the design considerations and trade-offs involved in developing a stratospheric airship with in-flight gas replenishment based on regenerative fuel cells (RFC). To address the challenge of lift gas leakage and enhance flight endurance, the primary aim is to optimize energy acquisition, storage, and buoyancy maintenance. A solution utilizing RFCs to supply lift gas has been proposed, leveraging the combined utilization of hydrogen for energy and buoyancy maintenance. The flight endurance model considering thermal effects, energy system and gas leakage is established to provide insights into its potential for extending the flight endurance of stratospheric airships by 25.5 % based on the design of Stratobus. Scaling up the energy system provides surplus energy for hydrogen production; however, it may impact gas-tightness due to increased weight allocation. Various weight configurations were evaluated, demonstrating the significant impact of weight distribution on endurance. Without gas replenishment, the longest endurance was 60.4 days. With increased energy storage distribution and gas replenishment consideration, endurance improved to 87.2 days. Furthermore, a longer flight endurance extension to 118.2 days can be reached by applying a gasbag storage system. This underscores the importance of exploring innovative storage solutions to achieve longer endurance.