Liquid Hydrogen Tank Layouts in Blended Wing Body Aircraft: Conceptual Design and Comparative Evaluation

Abstract

Hydrogen-fueled aircraft promise to achieve significantly reduced climate impact compared to their kerosene counterparts. However, while hydrogen has a significantly higher gravimetric density than kerosene, its volumetric density is much lower, meaning that even in a liquid state, it takes up approximately four times the volume. This results in significant challenges in integrating hydrogen storage in aircraft. It has been suggested that blended wing body (BWB) aircraft may provide a better-suited alternative for hydrogen integration compared to the conventional tube-and-wing (TAW) configuration. Prior research has investigated hydrogen-fueled BWB aircraft, highlighting different potential tank integration strategies. To the author's knowledge, no direct comparison of these hydrogen configurations highlights their relative performance impact compared to a consistent kerosene baseline aircraft. Therefore, this work compares different hydrogen tank configurations identified in prior research to a kerosene BWB baseline under consistent top-level aircraft requirements (TLARs), including a design range of 2500 nmi and 239 passengers. Technology assumptions for a 2050 entry into service (EIS) are applied. The analysis is complemented through the development of hydrogen and kerosene TAW configurations that fulfill the same TLARs. The comparison is performed in three steps. First, a BWB is designed for each tank configuration using conceptual design methods. Second, the four tank layouts are compared and the layout is identified that imposes the lowest energy penalty on the BWB. Third, the integration penalty of the hydrogen BWB is compared to that of the hydrogen TAW. A BWB employing a combined tank configuration, with hydrogen tanks located beside and aft of the passenger cabin, is found to experience the lowest integration penalty. The BWB experiences a 12.5 % penalty in block energy for the design mission, compared to a penalty of 10.5 % experienced by the TAW. This indicates that the BWB is less well suited to hydrogen integration than the TAW under the specified TLARs. In addition, sensitivity studies are conducted to evaluate the impact of integration assumptions on the BWB. These show that reasonable variations in the assumptions do not change the conclusion of this study. The findings do not eliminate hydrogen-fueled BWB aircraft as a viable alternative to hydrogen-fueled TAW designs. In fact, literature shows that BWB configurations still offer an inherent efficiency advantage, although their higher integration penalty must be considered in the overall trade-off.