Turbo-electric distributed propulsion – opportunities, benefits and challenges

Nomenclature

Symbols

CO= Carbon monoxide

CO₂ = Carbon dioxide

LH₂ = Liquid hydrogen

SO_x = Sulphur oxide

Definitions, acronyms and abbreviations

BRIC = Brazil Russia India China

GWP = Global warming potential

HWB = Hybrid wing body

HTS = High temperature superconductivity

TeDP = Turbo electric distributed propulsion

UHC = Unburnt hydrocarbons

Introduction

The World Bank report of November 2012 discusses the impact of the world being warmer by 4°C. Without serious policy changes and mitigation measures in place, this would be the predicted rise in temperature by the end of the century.

The predicted effects of this 4°C rise are devastating. It will result in highly unpredictable global weather patterns, which would increase the risk of large-scale seasonal changes and extreme natural calamities such as high-intensity tropical cyclones and further result in submergence of coastal areas through flooding. Every one of these effects will have serious and detrimental socio-economic implications. The report goes onto further state that with anticipated high uncertainty and new risks, it will threaten our ability to anticipate and plan for future adaptation needs. The lack of action on climate change not only risks putting prosperity out of reach of millions of around the world; it threatens to roll back decades of sustainable development (World Bank, 2012a).

As the world becomes increasingly concerned with climate change, international civil aviation’s contribution towards it is in focus. It has been estimated that civil aviation accounts for approximately 2-3 per cent of total anthropogenic CO₂ emissions and 12 per cent of the emissions from transportation sources (ICAO, 2013; IPCC, 2007).

Over the years, the industry has consistently invested in improving technology and infusing it into commercial application with an aim to always remain profitable. With fuel expenses being a significant part of an airlines operating cost, the core focus of technology development has been to constantly improve fuel economy, maintaining landing and takeoff (LTO) cycle noise and NO_x within certification limits and improving safety/reliability. Consequently, in the past 40 years, these improvements have led to a reduction of 70 per cent in fuel consumption and a decrease in noise by 75 per cent (Airbus, 2013).

Trends in the past 40-50 years have shown that the growth in air traffic...