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Micro Physical Modeling Of Aircraft Exhaust Plumes And Condensation Trails
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Book Synopsis Micro-physical Modeling of Aircraft Exhaust Plumes and Condensation Trails by : Thibaud M. Fritz
Download or read book Micro-physical Modeling of Aircraft Exhaust Plumes and Condensation Trails written by Thibaud M. Fritz and published by . This book was released on 2018 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ability to quantitatively assess the environmental impacts of air transport operations is necessary to estimate their current and future impacts on the environment. Emissions from aircraft engines are a significant contributor to atmospheric NOx driving climate change, air quality impacts and other environmental concerns. To quantify these effects, global chemistry-transport models are frequently used. However, such models assume homogeneous and instant dilution into large-scale grid cells and therefore neglect micro-physical processes, such as contrail formation, occurring in aircraft wakes. This assumption leads to inaccurate estimates of NOy partitioning, and thus, an over-prediction of ozone production. To account for non-linear plume processes, a Lagrangian aircraft plume model has been implemented. It includes a unified tropospheric-stratospheric chemical mechanism that incorporates heterogeneous chemistry. Micro-physical processes are considered throughout the entire plume lifetime. The dynamics of the plume are solved simultaneously using an operator splitting method. The plume model is used to quantify how the in-plume chemical composition is affected in response to various environmental conditions and different engine and/or fuel characteristics. Results demonstrate that an instant dilution model overestimates ozone production and accelerates conversion of nitrogen oxides compared to the plume model. Sensitivities to the NOx emission index have been derived and the dependence of the plume treatment on the background atmosphere mixing ratios, pressure and latitude has been investigated for a future regional scale assessment of the aviation sector. The cumulative impact of successive flights has been estimated. Contrail micro-physical and chemical properties have been computed under different scenarios. This aircraft plume model has been extensively validated and enables an in-depth assessment of the impact of one or multiple flights on local atmospheric conditions.
Book Synopsis Modeling Aircraft Contrails and Emission Plumes for Climate Impacts by : Alexander Dean Naiman
Download or read book Modeling Aircraft Contrails and Emission Plumes for Climate Impacts written by Alexander Dean Naiman and published by Stanford University. This book was released on 2011 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aircraft emissions lead to contrails and change cloud coverage in the upper troposphere/lower stratosphere, but their quantitative impact on climate is highly uncertain. As environmental policy turns toward regulating anthropogenic climate change components, it will be necessary to improve quantification of the climate impacts of aviation. Toward this end, we present two models of aircraft emissions. The first model is a large eddy simulation (LES) with three-dimensional, eddy-resolving flow physics and ice deposition/sublimation microphysics. Modeled ice properties, cloud optical depths, and contrail width growth rates are consistent with observational field studies. A series of sensitivity cases shows the effect of various parameters over twenty minutes of simulation time. The analysis focuses on properties such as contrail optical depth and cross-sectional width that are relevant to climate impacts. Vertical wind shear is found to have the strongest effect on these properties through the kinematic spreading of the contrail. In cases with no shear, optical depth is most sensitive to aircraft type and ambient humidity. One model parameter, the effective emission index of ice crystals, is also found to affect optical depth. A subset of the LES cases is run for two hours of simulation time to approach the scale of dynamical time steps modeled by global climate simulations. These cases use more realistic ice microphysics, including sedimentation, and forced ambient turbulence, both of which are processes that control contrail development at late times. The second model is a simple, low cost parameterization of aircraft plume dynamics, intended to be used as a subgrid plume model (SPM) within large scale atmospheric simulations. The SPM provides basic plume cross-section time advancement that has been used as a dilution model within a coupled global atmosphere-ocean climate simulation to study the effects of aviation on air quality and climate. Comparison to the twenty-minute and two-hour LES results demonstrates that the SPM captures important plume development characteristics under the effect of vertical shear and atmospheric turbulence.
Download or read book NASA Reference Publication written by and published by . This book was released on 1977 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The Atmospheric Effects of Stratospheric Aircraft: A First Program Report by : Michael J. Prather
Download or read book The Atmospheric Effects of Stratospheric Aircraft: A First Program Report written by Michael J. Prather and published by . This book was released on 1992 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Modeling Aircraft Contrails and Emission Plumes for Climate Impacts by : Alexander Dean Naiman
Download or read book Modeling Aircraft Contrails and Emission Plumes for Climate Impacts written by Alexander Dean Naiman and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Aircraft emissions lead to contrails and change cloud coverage in the upper troposphere/lower stratosphere, but their quantitative impact on climate is highly uncertain. As environmental policy turns toward regulating anthropogenic climate change components, it will be necessary to improve quantification of the climate impacts of aviation. Toward this end, we present two models of aircraft emissions. The first model is a large eddy simulation (LES) with three-dimensional, eddy-resolving flow physics and ice deposition/sublimation microphysics. Modeled ice properties, cloud optical depths, and contrail width growth rates are consistent with observational field studies. A series of sensitivity cases shows the effect of various parameters over twenty minutes of simulation time. The analysis focuses on properties such as contrail optical depth and cross-sectional width that are relevant to climate impacts. Vertical wind shear is found to have the strongest effect on these properties through the kinematic spreading of the contrail. In cases with no shear, optical depth is most sensitive to aircraft type and ambient humidity. One model parameter, the effective emission index of ice crystals, is also found to affect optical depth. A subset of the LES cases is run for two hours of simulation time to approach the scale of dynamical time steps modeled by global climate simulations. These cases use more realistic ice microphysics, including sedimentation, and forced ambient turbulence, both of which are processes that control contrail development at late times. The second model is a simple, low cost parameterization of aircraft plume dynamics, intended to be used as a subgrid plume model (SPM) within large scale atmospheric simulations. The SPM provides basic plume cross-section time advancement that has been used as a dilution model within a coupled global atmosphere-ocean climate simulation to study the effects of aviation on air quality and climate. Comparison to the twenty-minute and two-hour LES results demonstrates that the SPM captures important plume development characteristics under the effect of vertical shear and atmospheric turbulence.
Book Synopsis Numerical Modeling of Chemistry, Turbulent Mixing and Aerosol Dynamics in Near-field Aircraft Plumes by : Zheng Wang
Download or read book Numerical Modeling of Chemistry, Turbulent Mixing and Aerosol Dynamics in Near-field Aircraft Plumes written by Zheng Wang and published by . This book was released on 1998 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author :National Aeronautics and Space Administration (NASA) Publisher :Createspace Independent Publishing Platform ISBN 13 :9781724301871 Total Pages :216 pages Book Rating :4.3/5 (18 download)
Book Synopsis Modeling Macro- And Micro-Scale Turbulent Mixing and Chemistry in Engine Exhaust Plumes by : National Aeronautics and Space Administration (NASA)
Download or read book Modeling Macro- And Micro-Scale Turbulent Mixing and Chemistry in Engine Exhaust Plumes written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-27 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: Simulation of turbulent mixing and chemical processes in the near-field plume and plume-vortex regimes has been successfully carried out recently using a reduced gas phase kinetics mechanism which substantially decreased the computational cost. A detailed mechanism including gas phase HOx, NOx, and SOx chemistry between the aircraft exhaust and the ambient air in near-field aircraft plumes is compiled. A reduced mechanism capturing the major chemical pathways is developed. Predictions by the reduced mechanism are found to be in good agreement with those by the detailed mechanism. With the reduced chemistry, the computer CPU time is saved by a factor of more than 3.5 for the near-field plume modeling. Distributions of major chemical species are obtained and analyzed. The computed sensitivities of major species with respect to reaction step are deduced for identification of the dominant gas phase kinetic reaction pathways in the jet plume. Both the near field plume and the plume-vortex regimes were investigated using advanced mixing models. In the near field, a stand-alone mixing model was used to investigate the impact of turbulent mixing on the micro- and macro-scale mixing processes using a reduced reaction kinetics model. The plume-vortex regime was simulated using a large-eddy simulation model. Vortex plume behind Boeing 737 and 747 aircraft was simulated along with relevant kinetics. Many features of the computed flow field show reasonable agreement with data. The entrainment of the engine plumes into the wing tip vortices and also the partial detrainment of the plume were numerically captured. The impact of fluid mechanics on the chemical processes was also studied. Results show that there are significant differences between spatial and temporal simulations especially in the predicted SO3 concentrations. This has important implications for the prediction of sulfuric acid aerosols in the wake and may partly explain the discrepancy between past numerical studies ...
Author :National Aeronautics and Space Adm Nasa Publisher :Independently Published ISBN 13 :9781724089328 Total Pages :32 pages Book Rating :4.0/5 (893 download)
Book Synopsis Measurements of Nucleation-Mode Particle Size Distributions in Aircraft Plumes During Sulfur 6 by : National Aeronautics and Space Adm Nasa
Download or read book Measurements of Nucleation-Mode Particle Size Distributions in Aircraft Plumes During Sulfur 6 written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-09-27 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes the participation of the University of Denver in an airborne measurement program, SULFUR 6, which was undertaken in late September and early October of 1998 by the Deutsches Zentrum fur Luft und Raumfahrt (DLR). Scientific findings from two papers that have been published or accepted and from one manuscript that is in preparation are presented. The SULFUR 6 experiment was designed to investigate the emissions from subsonic aircraft to constrain calculations of possible atmospheric chemical and climatic effects. The University of Denver effort contributed toward the following SULFUR 6 goals: (1) To investigate the relationship between fuel sulfur content (FSC--mass of sulfur per mass of fuel) and particle number and mass emission index (El--quantity emitted per kg of fuel burned); (2) To provide upper and lower limits for the mass conversion efficiency (nu) of fuel sulfur to gaseous and particulate sulfuric acid; (3) To constrain models of volatile particle nucleation and growth by measuring the particle size distribution between 3 and 100 nm at aircraft plume ages ranging from 10(exp -1) to 10(exp 3) s; (4) To determine microphysical and optical properties and bulk chemical composition of soot particles in aircraft exhaust; and (5) To investigate the differences in particle properties between aircraft plumes in contrail and non-contrail situations. The experiment focused on emissions from the ATTAS research aircraft (a well characterized, but older technology turbojet) and from an in-service Boeing 737-300 aircraft provided by Lufthansa, with modem, high-bypass turbofan engines. Measurements were made from the DLR Dassault Falcon 900 aircraft, a modified business jet. The Atmospheric Effects of Aviation Program (AEAP) provided funding to operate an instrument, the nucleation-mode aerosol size spectrometer (N-MASS), during the SULFUR 6 campaign and to analyze the data. The N-MASS was developed at the University of Denver with the support of NOA
Book Synopsis Microphysical Modeling of Ultrafine Hydrocarbon-containing Aerosols in Aircraft Emissions by : Mina Jun
Download or read book Microphysical Modeling of Ultrafine Hydrocarbon-containing Aerosols in Aircraft Emissions written by Mina Jun and published by . This book was released on 2011 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt: Combustion engines emit precursors of ne particulate matter (PM) into the atmosphere. Numerous gaseous species, soot particles, and liquid aerosols in the aircraft exhaust are involved in PM formation, and these very ne, nanometer-size particles potentially have signicant impacts on climate, human health, and air quality. In particular, the organic content of the particles is important to determine physical and chemical properties of PM and consequently their potential impacts on the environment. The main objective of this thesis is to understand the role of organic compounds in PM evolution by developing a microphysical model that incorporates organic compounds into the formation mechanism of binary aqueous aerosols. While binary aerosol models with sulfuric acid and water have been widely studied, the understanding of the effect of organics on the formation and growth of aerosols is still insufficient. This work demonstrates important interactions and competitions in the formation of multi-component aerosols with organic compounds, sulfuric acid, and water in aircraft emissions. Hydrocarbon-containing aerosols have been identied as a major component of ground-level aircraft emission, especially at low power operations. This thesis describes selected surrogates of organic species and introduces estimation techniques for their thermophysical properties. The surrogates of organic species include water-insoluble hydrocarbons and water-soluble oxygenated hydrocarbons. Simulation results suggest that certain hydrocarbon compounds play an important role in the formation of aviation aerosol with interactions with both homogeneous sulfuric acidwater aerosols and soot particles in the organic-rich aircraft plume. Hydrocarbons contribute to the growth of existing homogeneous liquid particles, whereas their contribution to aerosol number density is negligible compared to that of sulfuric acid and water, which largely determine the formation of homogeneous aerosols. Also, low volatility hydrocarbons (e.g., benzopyrene, coronene) are observed to be partitioned into soot particles and induce competition with the uptake of water-soluble species, while light water-soluble oxygenated hydrocarbons enhance the uptake of water and sulfuric acid on soot particles.
Book Synopsis The Suppression of Aircraft Exhaust Trails by : C. E. Anderson
Download or read book The Suppression of Aircraft Exhaust Trails written by C. E. Anderson and published by . This book was released on 1954 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Aviation and the Global Atmosphere by : Joyce E. Penner
Download or read book Aviation and the Global Atmosphere written by Joyce E. Penner and published by Cambridge University Press. This book was released on 1999-06-28 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Intergovernmental Panel on Climate Change Special Report is the most comprehensive assessment available on the effects of aviation on the global atmosphere. The report considers all the gases and particles emitted by aircraft that modify the chemical properties of the atmosphere, leading to changes in radiative properties and climate change, and modification of the ozone layer, leading to changes in ultraviolet radiation reaching the Earth. This volume provides accurate, unbiased, policy-relevant information and is designed to serve the aviation industry and the expert and policymaking communities.
Book Synopsis Quantifying and Reducing the Uncertainties in Global Contrail Radiative Forcing by : Akshat Agarwal (Scientist in aeronautics and astronautics)
Download or read book Quantifying and Reducing the Uncertainties in Global Contrail Radiative Forcing written by Akshat Agarwal (Scientist in aeronautics and astronautics) and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The number of BC particles emitted by an aircraft engine is required to estimate the number of crystals that form in a contrail. Decreasing the number of crystals that form by 80% could reduce the contrail RF by 50%. The first part of this thesis develops an approach to estimate the number of particles emitted by an engine. Using two complementary datasets, I relate smoke number measurements to the BC mass concentration, quantify losses in the measurement system, and connect mass emissions to particle number emissions. The method is applied to existing BC measurements achieving an R2 of 0.80 and 0.82, respectively. Global BC emissions for all operations in 2015 were estimated to be 2.0 Gg/year (95% CI = 1.7 - 2.3) and 2.42 × 1026 particles/year (95% CI = 1.58 - 3.81 × 1026).
Book Synopsis The Atmospheric Effects of Stratospheric Aircraft by :
Download or read book The Atmospheric Effects of Stratospheric Aircraft written by and published by . This book was released on 1992 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Contrails and Climate Engineering - Process Studies on Natural and Artificial High-Level Clouds and Their Impact on the Radiative Fluxes by : Gruber, Simon
Download or read book Contrails and Climate Engineering - Process Studies on Natural and Artificial High-Level Clouds and Their Impact on the Radiative Fluxes written by Gruber, Simon and published by KIT Scientific Publishing. This book was released on 2019-03-22 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Atmospheric Effects of Aviation by : National Research Council
Download or read book Atmospheric Effects of Aviation written by National Research Council and published by National Academies Press. This book was released on 1999-03-19 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aviation is an integral part of the global transportation network, and the number of flights worldwide is expected to grow rapidly in the coming decades. Yet, the effects that subsonic aircraft emissions may be having upon atmospheric composition and climate are not fully understood. To study such issues, NASA sponsors the Atmospheric Effects of Aviation Program (AEAP). The NRC Panel on Atmospheric Effects of Aviation is charged to evaluate AEAP, and in this report, the panel is focusing on the subsonic assessment (SASS) component of the program. This evaluation of SASS/AEAP was based on the report Atmospheric Effects of Subsonic Aircraft: Interim Assessment Report of the Advanced Sub-sonic Technology Program, on a strategic plan developed by SASS managers, and on other relevant documents.
Download or read book Cirrus written by David K. Lynch and published by Oxford University Press, USA. This book was released on 2002 with total page 499 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text, devoted entirely to cirrus clouds, captures the state of knowledge of cirrus clouds and serves as a practical handbook as well.
Book Synopsis Atmospheric Effects of Aviation by : Anne M. Thompson
Download or read book Atmospheric Effects of Aviation written by Anne M. Thompson and published by . This book was released on 1996 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:
