Hydrogen Optimized multi-fuel Propulsion system for clean and silEnt aircraft

国际民航组织的后COVID预测估计，收入里程增长率从低到高将增加2. 4%-4. 1%。空中交通量的增长不可避免地增加了航空的燃烧和声发射，从而加剧了航空对当地和全球环境的影响。HOPE公司将提供一个综合的飞机推进系统，包括两个多燃料超高涵道比（UHBR）涡轮风扇发动机，一个基于燃料电池的辅助推进和动力装置（FC-APPU）驱动一个基于管翼飞机构型的后边界层摄入（BLI）推进器。HOPE系统：1）最小化着陆和起飞（LTO）期间的燃烧和噪声排放，因此对机场附近的空气质量和噪声烦恼的影响最小化，而不权衡巡航排放; 2）改造现有的飞机配置，允许在短时间内实现大幅减排; 3）降低仅在现有管翼飞机配置中使用氢的风险; 4）通过评估和开发不同成熟度的绿色推进技术，使航空能源转型更加顺畅。HOPE的排放目标包括：与2020年最先进的技术（A320 neo）相比，LTO NOx：-50%，CO：-50%，烟尘：-80%，感知噪音：-20%（每次操作约3 dB），气候影响：-30%。为此，希望将：1）设计一种适应多种燃料的综合飞机推进系统（煤油/可持续航空燃料+氢气）UHBR涡轮风扇发动机、FC-APPU和后部BLI推进器; 2）探索BLI推进器与FC-APPU结合以实现零排放滑行的新想法; 3）首次模拟、试验和演示用于未来UHBR涡轮风扇发动机的燃烧H2+煤油/SAF的低排放多燃料燃烧技术; 4）评估HOPE技术降低噪音和排放的社会影响、环境负担和成本效益; 5）制定政策和建议，以引入HOPE技术。

The ICAO Post-COVID forecasts estimate a 2.4%-4.1% increase for a low to high revenue passenger-kilometres growth rate. Air traffic growth inevitably increases aviation's combustion and acoustic emissions, hence aggravating aviation's environmental impact locally and globally. HOPE will deliver an integrated aircraft propulsion system comprising two multi-fuel ultra-high bypass ratio (UHBR) turbofan engines, a fuel cell based auxiliary propulsion and power unit (FC-APPU) driving an aft boundary layer ingestion (BLI) propulsor based on tube-wing aircraft configuration. The HOPE system: 1)minimises the combustion and noise emissions during landing and takeoff (LTO), hence the impact on air quality and noise annoyance near airports, without the trade-off of cruise emissions; 2)retrofitsthe existing aircraft configuration, allowing the substantial emission reduction to be achieved within a short time; 3)de-risks the use of hydrogen solely in existing tube-wing aircraft configurations; 4)smoothens aviation’s energy transition through assessment and exploitation of several greener propulsion technologies at different maturity level. HOPE emission goals consist of LTO NOx: -50%, CO: -50%, soot: -80%, perceived noise: -20% (~3 dB per operation), and climate impact: -30%, compared to state-of-the-art technology in 2020 (A320neo). To this end, HOPE will: 1)Design an integrated aircraft propulsion system accommodating multi-fuel (kerosene/sustainable aviation fuel +hydrogen) UHBR turbofan engines, FC-APPU, and an aft BLI propulsor; 2)Explore the novel idea of combining a BLI propulsor with FC-APPU for zero-emission taxiing; 3)Model, experiment, and demonstrate for the first time a low emission multi-fuel combustion technology burning H2+kerosene/SAF for future UHBR turbofan engine; 4)Assess societal impact, environmental burden, and cost benefits of the reduced noise and emissions by HOPE technology; 5)Formulate policy and recommendations to introduce HOPE technology.