UC Irvine

Aviation contributes approximately 2.4% of global CO2 emissions, and with the anticipated increasein flight demand, these emissions are expected to grow significantly, posing a major challenge for the industry’s sustainability. Hydrogen propulsion has emerged as a promising solution to mitigate the environmental impact of aviation by providing a pathway toward zero-emission flight. The exploration of this potential is conducted via a multifaceted approach, encompassing the modeling, performance analysis and retrofit of existing aircraft, the development of next-generation configurations, and the dynamic, electrochemical modeling of conceptualized hydrogen fuel cell powertrain. Additionally, it includes the techno-economic analysis for the transformation of airport infrastructure to support hydrogen-powered aviation, advancing the integration of hydrogen technologies across the aviation ecosystem. This approach ensures a holistic understanding of hydrogen’s potential and challenges in revolutionizing the aviation sector. The research begins with a detailed retrofitting methodology applied to a Cessna Citation XLS+, incorporating hybrid systems that combine hydrogen combustion with Solid Oxide Fuel Cell/Gas Turbine (SOFC/GT) technology. Technical modifications, such as designing cryogenic liquid hydrogen tanks with optimized insulation, sizing, and center of gravity adjustments, achieve a 5% reduction in takeoff weight for hydrogen combustion and a 0.4% reduction for the SOFC hybrid configuration, albeit with reduced passenger capacity to accommodate the tanks. These modifications reveal critical trade-offs in aircraft design, highlighting the balance between weight reduction and capacity. Building on this foundation, dynamic modeling of a Cessna S550 Citation S/II equipped with an SOFC/GT system evaluates the system’s ability to manage real-time flight dynamics, demonstrating efficiency peaks of up to 71.4% while underscoring the essential role of battery integration to support rapid power needs during takeoff, descent, and landing. This study provides a valuable contribution to understanding the integration and operational efficiency challenges of hydrogen fuel cell systems in aviation. The research then explores innovative Blended Wing Body (BWB) designs, specifically the BWB-365 and BWB-162 models, revealing fuel efficiency improvements of 22.7% and 28.7%, respectively, over traditional designs. It also identifies the challenges of integrating SOFC/GT powertrains with hydrogen storage into sized Tube-&-Wing aircraft, which may require fuselage modifications to maintain payload capacity, offering insights into the design considerations for future hydrogenpowered aircraft. Further retrofit analysis is conducted on the ATR42-600, a regional turboprop, retrofitted with hydrogen power systems. Comparisons between PEMFC, SOFC/GT, hydrogen combustion, and battery-electric configurations reveal significant trade-offs, particularly highlighting the limitations of battery-electric technology for regional aircraft. The narrative culminates in a techno-economic assessment of green hydrogen supply infrastructure at Los Angeles International Airport, projecting that advancements in renewable energy capacity and optimized hydrogen logistics could lower the Levelized Cost of Hydrogen (LCOH) to $3.65/kg by 2050 with a year-round hourly analysis and potentially decreasing further based on seasonal storage methods. This comprehensive analysis provides a pathway to realizing sustainable aviation, balancing technical feasibility, economic viability, and environmental impact.