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.

The aviation industry is currently facing significant pressure to enhance its sustainability by increasing aircraft energy efficiency and reducing its climate impact. A promising approach to fulfilling these demands is to improve the aircraft's aerodynamic performance through drag reduction by implementing laminar flow technologies, particularly Natural Laminar Flow (NLF) or Hybrid Laminar Flow Control (HLFC).
Prior works assessing laminar flow technologies have mostly focused on evaluating their aerodynamic performance and, in the case of the HLFC, on the influence of system design. The impact of these technologies on the overall aircraft performance has received only limited consideration, with the majority of studies focusing on long-range aircraft, utilizing simplified models for HLFC systems, and considering only one laminar flow technology at a time.
This study adopts a holistic approach to assess the potential fuel savings that could be achieved by combined application of NLF and HLFC technologies on the various components of a short-to-medium range aircraft concept, with an intended entry into service in 2035. To achieve this objective, a conceptual aircraft design process is employed. This process captures the aerodynamic effects of laminar flow technologies and fully integrates the HLFC system design to provide an accurate estimate of aircraft performance.
The findings of this study reveal a potential for fuel savings of 5.9\% on the design mission through the combined application of NLF and HLFC, compared to a turbulent aircraft with an equivalent technology level. Additionally, the results indicate that strategic combination of the two technologies on a single component can significantly reduce complexity while further enhancing fuel savings. A failure analysis also provides an initial estimate of the impact of various failure scenarios on the aircraft's performance.
These findings demonstrate that, despite the aircraft's short range, the combined implementation of the two laminar flow technologies offers a potential for fuel savings with reduced complexity, motivating further research in their application to this aircraft category.