New non-volatile Particulate Matter (nvPM) regulation has recently been adopted by ICAO (CAEP 11) for the regulation of Aircraft engines (>26.7kN thrust). The sampling and measurement protocols specify a standardised sample line length of up to 35 m, which coupled with the small GMD of nvPM witnessed from gas turbines (20-50nm)[[i]] result in significant particle loss. Engine exit nvPM concentrations facilitate inter-comparison of different engine technologies and power settings which display varying nvPM size distributions and are crucial in understanding aviation impact on local air quality. A System Loss Tool for the ICAO compliant measurement system has been proposed by the SAE E31[[ii]] which predicts a size distribution using assumptions of particle density and Geometric Standard Deviation (GSD). The impacts of measurement uncertainty, assumed particle effective density, GSD and lognormality were investigated. This work highlights the potential for improved loss correction methodology using a size measurement not currently prescribed by regulation.
[i] Lobo P, Durdina L, Smallwood G J, Rindlisbacher T, Siegerist F, Black E A, Yu Z, Mensah A A, Hagen D E, Miake-Lye R C, Thomson K A, Brem B T, Corbin J C, Abegglen M, Sierau B, Whitefield P D & Wang J (2015) Measurement of Aircraft Engine Non-Volatile PM Emissions: Results of the Aviation-Particle Regulatory Instrumentation Demonstration Experiment (A-PRIDE) 4 Campaign, Aerosol Science and Technology, 49:7, 472-484.
[ii] SAE INTERNATIONAL: ARP6481 – Procedure for the Calculation of Non-Volatile Particulate Matter Sampling and Measurement System Losses and System Loss Correction Factors. 25/02/2019, DOI: 10.4271/ARP6481.