Hydrogen and Ammonia Powered Turbofan Design Implications for Next Generation of Aircraft Engines

Abstract This paper aims to establish the cycle design implications for turbofan engines that will be powered by hydrogen and ammonia. Appropriate methodologies are employed to address the identified research questions. A comprehensive turbofan design space exploration is performed for hydrogen and ammonia. An evaluation of engine size and weight is carried out for both hydrogen and ammonia, with the support of three distinct turbofan design strategies. The impact of fan size (specific thrust) on the cycle design of turbofan engines powered by hydrogen and ammonia is assessed. The turbofan design opportunities when powered by hydrogen across aircraft category is explored. The impact of fan size and the cryogenic tank technology on a hydrogen aircraft is investigated. It is identified that hydrogen and ammonia offered three main turbofan design opportunities. Hydrogen and ammonia significantly affects the engine size, weight, and operating temperatures based on the design strategy selected. With similar ESFC breakpoints for very low specific thrust values, hydrogen and ammonia showcases significant departure in bypass ratios (BPRs) from kerosene for all ranges of fan sizes. Hydrogen offers significant turbofan redesign opportunities across aircraft category (short medium range (SMR) and long range (LR)). Cryogenic tank technology is a major design driver for both hydrogen turbofan and aircraft mission energy burn.