Hydrogen aircraft concepts and ground support

Abstract

As worldwide petroleum supplies diminish and prices escalate, the aviation industry will be forced to consider relying on energy resources other than kerosene for its aviation fuel needs. Additionally, there is growing environmental concern regarding greenhouse emissions particularly as aircraft cause pollution in sensitive layers of the atmosphere. These are serious implications necessitating prudence in seeking alternative fuels sooner rather than later. Liquid Hydrogen (LH2) combustion produces zero CO2 emissions, very little NOx, and water providing a solution to sustain air traffic growth whilst preventing further atmospheric pollution. Hydrogen itself is abundant and can be produced from renewable sources meaning worldwide availability and sustainability permitting sustainable growth of aviation at high rates (typically 4-5% per year). Despite these major advantages, there are compromises to be made. The low density fuel means ingenuity must be exercised to design an aircraft configuration which will accommodate a fuel volume more than four times that which would normally be required. Practical unconventional aircraft conceptual designs providing solutions to this problem are presented including estimates of performance, mass, and relative cost- and energy-effectiveness. To provide a means to produce, store and transport the fuel safely and efficiently, ground support operations have been systematically checked and the required airport infrastructure defined. Technical issues such as safety, airworthiness certification, environmental issues and system synergies are also discussed, and an outline plan is presented providing the R&D necessary to introduce LH2-fuelled civil aircraft into service. This Thesis proves that LH2 has sufficient long term promise to justify more substantial R&D offering possible improvement in performance and engine reliability. The overall cost for a LH2 aircraft are within reasonable values, and the requirement for new equipment to maintain and support LH2-fuelled aircraft is not extensive. Importantly LH2 is at least as safe.