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Technical Paper

Prediction of Pollutant Concentration Variation Inside a Turbulent Dispersing Plume Using PDF and Gaussian Models

2002-03-04
2002-01-0654
In order to evaluate the impact of emission of pollutants on the environment, it has become increasingly important that the dispersion of pollutants be predicted accurately. Recently, USEPA has proposed stringent guidelines for regulating the diesel exhaust emissions, specifically, NOx, COx, SOx, and particulate matter (PM) due to green house effect, and ozone depletion. Modeling pollutant transport in the atmospheric environment is complicated by the fact that there are many turbulent mixing time scales and spatial scales present which directly influence the dispersion of the plume. The traditional approach to predicting pollutant dispersion in the atmosphere is the use of Gaussian plume models. The Gaussian models are based on a steady state assumption, and they require the flow to be in a homogeneous and stationary turbulence state.
Technical Paper

Effect of Ambient Dilution on Coagulation of Particulate Matter in a Turbulent Dispersing Plume

2002-03-04
2002-01-0652
In recent years, there has been an increasing need for accurately predicting the nucleation, coagulation, and dynamics of particulate matter (PM) emissions from diesel engines. The proposed United Sates Environmental Protection Agency (USEPA) standard on fine particles, is focused on allowing levels of 50 μg/m3 annual average concentration of PM10 (particles smaller than 10 μm aerodynamic diameter) and an additional annual average standard of 15 μg/m3 of fine particles smaller than 2.5 μm in the atmosphere. Existing legislation for particulates is however, based on measurement by mass but not on the particle number density. The current system does not properly account for the small particulates, mostly of the nucleation type, which have an insignificant mass despite being present in very high numbers. These small particulates in high numbers can contribute extremely large surface areas for biological interaction, and they can pose a serious health threat.
Technical Paper

Hybrid Projectile Transformation Condition Detection System for Extended Selectable Range

2013-09-17
2013-01-2203
A Hybrid Projectile (HP) is a tube launched munition that transforms into a gliding UAV, and is currently being researched at West Virginia University. In order to properly transform, the moment of transformation needs to be controlled. A simple timer was first envisioned to control transformation point for maximum distance. The distance travelled or range of an HP can directly be modified by varying the launch angle. In addition, an internal timer would need to be reprogrammed for any distance less than maximum range due to the nominal time to deployment varying with launch angle. A method was sought for automatic wing deployment that would not require reprogramming the round. A body angle estimation system was used to estimate the pitch of the HP relative to the Earth to determine when the HP is properly oriented for the designed glide slope angle. It also filters out noise from an inertial measurement unit (IMU).
Technical Paper

A Finite Element Modeling Approach for Stability Analysis of Partially Filled Tanker Trucks

1999-11-15
1999-01-3708
The rollover threshold for a partially filled tanker truck carrying fluid cargo is of great importance due to the catastrophic nature of accidents involving such vehicles, particularly when payloads are toxic and flammable. In this paper, a method for determining the threshold of rollover stability of a specific tanker truck is presented using finite element analysis methods. This approach allows the consideration of many variables which had not been fully incorporated in past models, including nonlinear spring behavior and tank flexibility. The program uses simple mechanical pendulums to simulate the fluid sloshing affects, beam elements to match the torsional and bending stiffness of the tank, and spring damper elements to simulate the suspension. The finite element model of the tanker truck has been validated using data taken by the U.S. Army Aberdeen Test Center (ATC) on a M916A1 tractor/ Etnyre model 60PRS 6000 gallon trailer combination.
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