The air-travel demand is predicted to increase in future with an annual worldwide average growth rate of approximately 4.5%, during 2017-2036 timeframe. This growth in air-travel will increase aviation’s climate change impacts. According to the intergovernmental panel on climate change (IPCC), aviation currently contributes to 5% of total man-made climate change impacts which is predicted to increase to 7% in the year 2050. Additionally, aircraft emissions are responsible for around 16,000 premature deaths a year due to impaired air quality, according to research from MIT. My PhD research is a multi-disciplinary problem for minimizing the human and environmental health impacts of future civil aviation. I am evaluating the potential of futuristic and advanced/ultra-energy-efficient civil-aircraft technologies and alternative aviation fuels towards carbon neutrality and reducing air-quality impacts of aviation. I develop aircraft performance/mission fuel-burn models of future large twin-aisle aircraft architectures (viz. blended/hybrid wing body aircraft) with a capacity of 300 passengers. In addition to the future aircraft architectures, I examine the potential of hybrid-electric and full-electric propulsion, ultra-high bypass ratio turbofan engines, and ion propulsion for future civil-aviation use. In terms of alternative aviation fuels, I am examining: biomass-derived ASTM approved blended jet fuels, 100% synthetic paraffin kerosene, power-to-liquid fuel, and liquid hydrogen, along with their holistic impacts. There are certain alternative fuels (like liquid hydrogen, 100% synthetic paraffin kerosene, etc.) which have special needs in terms of its use in aircraft and therefore need aircraft/airframe redesign. Liquid hydrogen is a special fuel because its gravimetric energy density is 2.78 times higher than conventional jet fuel but the volumetric energy density of conventional jet fuel is 4.1 times higher than liquid hydrogen. This implies that more volume is required to store the required (liquid hydrogen) flight-mission fuel on an aircraft, which is a major engineering challenge that is being addressed by me.
This research is in-line with NASA’s ‘N+i’ goals for environmentally responsible aviation, and with the objectives of UN's Paris-treaty on climate-change. The N+i goals and timeframes are tabulated below. Presently, one Los Angeles - Mumbai return air-travel emits a similar amount of greenhouse gas a car in the USA or UK emits on an annual basis, and my PhD research can reduce aircraft’s carbon-footprint by at least 50% and can potentially decarbonize the aviation sector. Therefore, my PhD research is impactful and significant globally.
|Corners of the trade space||N+1 (service entry year 2020 and beyond) technology benefits relative to a single aisle reference configuration (Boeing 737/CFM 56)||N+2 (year 2025 and beyond) technology benefits relative to a large twin aisle reference configuration (Boeing 777/GE 90)||N+3 (year 2030 and beyond) technology benefits|
|Noise||-32 dB||-42 dB||-71 dB|
|LTO NOx emissions (below CAEP 6)||-60%||-75%||Better than -75%|
|Performance (Aircraft fuel burn)||-33%||-50%||Better than -70%|