Exhaust Emissions From In Use General Aviation Aircraft

Background -- Research approach -- Trends in emission indices -- Sensitivity analysis on airport emissions -- Other parameters affecting emissions -- Conclusions -- Appendix A: Engine prioritization list -- Appendix B: Test matrix -- Appendix C: ICAO vs. FOCA databases -- Appendix D: Method for calculating emission ratios -- Appendix E: Method for calculating emission ratios -- Appendix F: Variability in emissions results from variability in the engine -- Appendix G: Gas-phase measurement instrument -- Appendix H: PM measurement instruments -- Appendix I: PM line losses -- Appendix J: Estimating fuel flows for piston engines -- Appendix K: Carbon content of AVGAS 100 LL -- Appendix L: Hypothetical airport engine mapping -- Appendix M: Terminology and abbreviations -- Appendix N: References -- Appendix O: List of data products -- Appendix P: Emission index data tables

Works related to identification of harmful exhaust components from aviation engines have continued since the second half of the last century. These works focus on high-thrust turbine engines. For this, group testing and standardization procedures have been developed containing the admissible limits of exhaust components. Since 2007 works have been underway related to the identification of harmful exhaust components from engines of low power output that have not yet been included in the emissions legislation. These actions are particularly related to the measurements of the exhaust emissions from piston aviation engines and they are focused on the fuel applied for these engines. This book presents the results of the author's own research work related to the issues of exhaust emissions from powertrains of aircraft and helicopters fitted with piston or turbine engines not yet included in the emission legislation. Research has been presented for turbocharged piston and jet engines aircraft. Test procedures have been presented related to the measurement of the exhaust emission under actual conditions of operation. The study presents analyses of the operating conditions of aviation engines, for which data from the on-board recording devices (flight parameters) have been used. Tests have been developed related to the engines operating under actual operating (in-flight) conditions. The methodology of the developed test has been validated based on a test dedicated for an aircraft fitted with a jet engine. The test results have been subject to a comparison with the results of tests applicable in the homologation procedures. Eventually, the authors proposed exhaust emissions tests dedicated to individual aircraft groups.

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, industry and academia 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 maintenance logistics dictate the drive for "drop-in" fuels, blending jet-grade and biofuel. New certification standards for alternative 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.