Green Aviation ─ Reduction of Environmental Impact Through Aircraft Technology and Alternative Fuels

Aircraft emissions currently account for ~3.5% of all greenhouse gas emissions. The number of passenger miles has increased by 5% annually despite 9/11, two wars and gloomy economic conditions. Since aircraft have no viable alternative to the internal combustion engine, improvements in aircraft efficiency and alternative fuel development become essential.
This book comprehensively covers the relevant issues in green aviation. Environmental impacts, technology advances, public policy and economics are intricately linked to the pace of development that will be realized in the coming decades. Experts from NASA and industry review current technology development in green aviation that will carry the industry through 2025 and beyond. This includes increased efficiency through better propulsion systems, reduced drag airframes, advanced materials and operational changes. Clean combustion and emission control of noise, exhaust gases and particulates are also addressed through combustor design and the use of alternative fuels. Economic imperatives from aircraft lifetime and maintaince logistics dictate the drive for "drop-in" fuels, blending jet-grade and biofuel. New certification standards for such fuels are outlined. Life Cycle Assessments are used to evaluate worldwide biofuel approaches, highlighting that there is no single rational approach for sustainable buildup. In fact, unless local conditions are considered, the use of biofuels can create a net increase in environmental impact as a result of biofuel manufacturing processes. Governmental experts evaluate current and future regulations and their impact on green aviation. Sustainable approaches to biofuel development are discussed for locations around the globe, including the US, EU, Brazil, China and India.

Emily S. Nelson is a research engineer at the NASA Glenn Research Center (GRC) specializing in interdisciplinary research at the intersection of fluid mechanics and heat transport, materials science, biology and/or human physiology. She received her B.S. in Mechanical Engineering from the Illinois Institute of Technology, Chicago, IL (1983); M.S. in Mechanical Engineering from the Illinois Institute of Technology (1986); and her Ph.D. in Mechanical Engineering from the University of California at Berkeley (1998). Dr. Nelson has been employed as a research engineer by NASA GRC since 1989. She is conducting numerical simulations of industrial algae growth processes, which combine hydrodynamics with biokinetics to evaluate and develop system designs and operating protocols for biomass yield, consumption of waste CO2 generated by a power plant, and power requirements.

Dhanireddy Ramalinga "D.R" Reddy, Chief of the Aeropropulsion Division at NASA Glenn Research Center , Cleveland, Ohio, is responsible for providing enabling capabilities to the aerospace community by leading research and developing technology in the areas of turbomachinery, combustion, fuels/propellants, icing, inlets, nozzles, propulsion system simulation, engine systems, and computational methods. He received his Bachelor of Engineering in Mechanical Engineering (1971) from Sri Venkateswara University, A. P., India; Master of Engineering in Aeronautical Engineering (1974) from Indian Institute of Science, Bangalore; and Ph.D. in Aerospace Engineering (1983) from the University of Cincinnati. Dr. Reddy joined NASA GRC in 1991, serving as Chief of the Computational Fluid Dynamics Branch and Senior Consultant, and focusing research on developing a predictive capability to accurately simulate the complex flow features of advanced aerospace propulsion systems.