Abstract-We report on the installation and commissioning of two systems for the measurement of cross-sectional distributions of pollutant species in jet exhaust, within the engine ground test facility at INTA, Madrid. These systems use optical tomography techniques to estimate the cross-sectional distributions of CO 2 and soot immediately behind the engine. The systems are designed to accommodate the largest civil aviation engines currently in service, without obstruction of the exhaust or bypass flows and with negligible effect upon the entrained flow behavior. We describe the physical construction and installation status of each system. In the case of the CO 2 system, we examine the challenges of achieving the structural rigidity necessary for adequate suppression of pointing error within 126 laser-based transmittance measurements, each utilizing a 7 m overall path length. We describe methods developed for efficient implementation of co-planarity and 4-degree-of-freedom alignment of individual paths within this beam array. We also present laboratory performance data for three alternative optical designs that differ in their approach to the management of pointing error and turbulence-induced beam wander and spread. The FLITES soot monitoring capability is based on laser induced incandescence (LII) and uses a short-pulse fiber laser and two CCD cameras, in an autoprojection arrangement. We describe the measurement geometry currently being implemented in the test cell and discuss optical design issues, including once again the effect of the plume itself.

COUNTERFOG® has been proposed as a rapid decontamination and disinfection technology that uses dynamic submicrometric-disinfecting fog cones. When projected onto surfaces, they create a micrometre-thick film of disinfectant minimizing the use of liquids and the impact on environment. The extremely thin film is intended to be enough to cover and kill microorganisms and simultaneously thin enough to evaporate in a few minutes-depending on the environmental conditions. In the present work, experimental tests were carried out to verify this hypothesis. These include a physical characterization of the fog in the cone, a measurement of the liquid flow projected on surfaces as well as disinfection tests with a series of microorganisms. In addition to these results, operational recommendations are derived to ensure disinfection reliability.

Emissions from aircraft have adverse effects on the air quality in and around airports, contributing to public health concerns within neighbouring communities. AVIATOR will adopt a multi-level measurement, modelling and assessment approach to develop an improved description and quantification of the relevant aircraft engine emissions, and their impact on air quality under different climatic conditions. Particulate and gaseous emissions in a test cell and on-wing from an in-service aircraft will be measured to determine pollutant plume evolution from the engine and APU exhaust. This will provide an enhanced understanding of primary emitted pollutants, specifically the nvPM and vPM (down to 10nm), and the scalability between the regulatory test cell and real environments. AVIATOR will develop and deploy a proof-of-concept low cost sensor network for monitoring UFP, PM and gaseous species across multiple airports and surrounding communities. Campaigns will be complemented by high-fidelity modelling of aircraft exhaust dynamics, microphysical and chemical processes within the plume. CFD, box, and airport air quality models will be applied, providing validated parameterisations of the relevant processes, applicable to standard dispersion modelling on the local scale. Working with the regulatory community, AVIATOR will develop improved guidance on measuring and modelling the impact of aircraft emissions, and will provide airports and regulators with tools and guidance to improve the assessment of air quality in and around airports.

A miniaturized analytical procedure to determine selected polycyclic aromatic compounds (PACs) in low mass loadings (<10 mg) of particulate matter (PM) is evaluated. The proposed method is based on a simple sonication/agitation method using small amounts of solvent for extraction. The use of a reduced sample size of particulate matter is often limiting for allowing the quantification of analytes. This also leads to the need for changing analytical procedures and evaluating its performance. The trueness and precision of the proposed method were tested using ambient air samples. Analytical results from the proposed method were compared with those of pressurized liquid and microwave extractions. Selected PACs (polycyclic aromatic hydrocarbons (PAHs) and nitro polycyclic aromatic hydrocarbons (NPAHs)) were determined by liquid chromatography with fluorescence detection (HPLC/FD). Taking results from pressurized liquid extractions as reference values, recovery rates of sonication/agitation method were over 80% for the most abundant PAHs. Recovery rates of selected NPAHs were lower. Enhanced rates were obtained when methanol was used as a modifier. Intermediate precision was estimated by data comparison from two mathematical approaches: normalized difference data and pooled relative deviations. Intermediate precision was in the range of 10-20%. The effectiveness of the proposed method was evaluated in PM aerosol samples collected with very low mass loadings (<0.2 mg) during characterization studies from turbofan engine exhausts.

Quantification of aero-engine emission is typically carried out using etfractive sampling resulting in poor spatio-temporal resolution. Here we present recent images obtained using non-intrusive chemical species tomography on a large-scale commercial aero-engine.