Structural and Thermal Optimization of Dual-Lined Cryogenic Fuel Tanks for Mid-Sized Commercial Aircraft

The transition to sustainable aviation fuels brings engineering challenge with the storage and transportation of cryogenic replacements like liquid ammonia. This paper presents a dual-lined cryogenic fuel tank with a stainless-steel inner layer for chemical compatibility and a carbon fiber composite case for light weight and strength. Structural and thermal performance is maximized through FEA to analyze thermal contraction and dynamic loads stress, and CFD models simulating heat ingress and boil-off. Integrated safety features include ammonia leak sensors and automatic isolation valves. Triple-walled tanks are compared to the design and demonstrate improved thermal and weight performance. Retrofit suitability is evaluated for the narrow-body plane, using the Boeing 737 MAX 8 as a reference platform, offering a viable path toward certifiable cryogenic storage for zero-emission flight.