Open Access. Powered by Scholars. Published by Universities.®
- Institution
- Keyword
-
- Adaptive--Mathematical models (1)
- Aerosol (1)
- Aircraft engine (1)
- Aircraft exhaust emissions (1)
- Airplanes (1)
-
- Atmospheric turbulence.Interferometers (1)
- Automobiles (1)
- Cebtral finite volume (1)
- Combustion (1)
- Diesel engine (1)
- Diesel motor exhaust gas (1)
- Electromagnetic noise (1)
- High order methods (1)
- Laser beams--Atmospheric effects (1)
- Mathematical models (1)
- Non-oscillatory (1)
- Numerical modeling (1)
- Optical communications (1)
- Optical radar--Computer simulation (1)
- Optics (1)
- Positivity preserving (1)
- Shallow water model (1)
- Soot (1)
- Transport problem (1)
- Turbulence characteristics; GPS dropwindsonde; Hurricane boundary layer; Direct observation; Numerical simulation; Turbulence model (1)
Articles 1 - 5 of 5
Full-Text Articles in Atmospheric Sciences
Implementation Of Branch-Point-Tolerant Wavefront Reconstructor For Strong Turbulence Compensation, Michael J. Steinbock
Implementation Of Branch-Point-Tolerant Wavefront Reconstructor For Strong Turbulence Compensation, Michael J. Steinbock
Theses and Dissertations
Branch points arise in optical transmissions due to strong atmospheric turbulence, long propagation paths, or a combination of both. Unfortunately, these conditions are very often present in desired operational scenarios for laser weapon systems, optical communication, and covert imaging, which suffer greatly when traditional adaptive optics systems either cannot sense branch points or implement non-optimal methods for sensing and correcting branch points. Previous research by Pellizzari presented a thorough analysis of various novel branch point tolerant reconstructors in the absence of noise. In this research a realistic model of the Air Force Institute of Technology's adaptive optics system is developed …
A Study On The Turbulent Characteristics Within The Hurricane Boundary Layer, Sunwei Li
A Study On The Turbulent Characteristics Within The Hurricane Boundary Layer, Sunwei Li
Electronic Thesis and Dissertation Repository
As the medium between the sea surface and the upper atmosphere in a hurricane, the Hurricane Boundary Layer (HBL) plays a key role in the overall dynamics of a tropical cyclone, and therefore turbulence exchanges within the HBL deserve a thorough investi- gation. However, since it is dangerous and difficult to take direct measurements within the HBL, studies of the HBL turbulence processes based on direct observations are rare. Thanks to the newly developed dropwindsonde equipped with a Global Position System (GPS) receiver, it is now possible to measure wind velocities and other meteorological variables with an unprecedented accuracy and …
Ladar Performance Simulations With A High Spectral Resolution Atmospheric Transmittance And Radiance Model- Leedr, Benjamin D. Roth
Ladar Performance Simulations With A High Spectral Resolution Atmospheric Transmittance And Radiance Model- Leedr, Benjamin D. Roth
Theses and Dissertations
In this study of atmospheric effects on Geiger Mode laser ranging and detection (LADAR), the parameter space is explored primarily using the Air Force Institute of Technology Center for Directed Energy's (AFIT/CDE) Laser Environmental Effects Definition and Reference (LEEDR) code. The LADAR system is assessed at operationally representative wavelengths of 1.064, 1.56 and 2.039 μm with several up and down looking engagement geometries at locations worldwide. Results computed with LEEDR are compared to standard atmosphere and Fast Atmospheric Signature Code (FASCODE) assessments. Results show significant climate dependence, but large variances between climatological and standard atmosphere assessments. An overall average absolute …
High-Order Central Finite-Volume Schemes For Atmospheric Modeling, Kiran Kumar Katta
High-Order Central Finite-Volume Schemes For Atmospheric Modeling, Kiran Kumar Katta
Open Access Theses & Dissertations
Atmospheric numerical modeling has been going through drastic changes over the past decade, mainly to utilize the massive computing capability of the petascale systems. This obliges the modelers to develop grid systems and numerical algorithms that facilitate exceptional level of scalability on these systems. The numerical algorithms that can address these challenges should have the local properties such as the high on-processor operation count and minimum parallel communication i.e., high parallel efficiency. They should also satisfy the following properties such as inherent local and global conservation, high-order accuracy, geometric flexibility, non-oscillatory advection and positivity preservation properties. The goal of this …
Detailed Modeling Of Soot Size Distribution Evolution And Pollutant Formation Inside Aircraft And Diesel Engines, Chowdhury Golam Moniruzzaman
Detailed Modeling Of Soot Size Distribution Evolution And Pollutant Formation Inside Aircraft And Diesel Engines, Chowdhury Golam Moniruzzaman
Legacy Theses & Dissertations (2009 - 2024)
Combustion emission of soot and pollutant gas species contributes to poor regional air quality near emission sources and to climate change. It is important to understand the formation mechanism and time evolution of these pollutants inside the combustion engine, through detailed modeling of combustion chemistry and microphysics as well as comparison with observation. In this thesis, two multi-zone gas parcel combustion engine models, one for aircraft engines and another for diesel engines, have been developed to study soot size distribution evolution and pollutant formation inside the engines as well as emissions. The models take into account size-resolved (sectional) soot aerosol …