Gaussian plume

Gaussian mode Gaussian plume model Gauss-Seidel Gauzes Gaylusite... 

Atmospheric stabUity can be examined utilising the Gaussian Plume model which ignores possible transformations ... 

Gaussian Plume Model. One of the most basic and widely used transport models based on equation 5 is the Gaussian plume model. 

Gaussian plume models for continuous sources can be obtained from statistical arguments or can be derived by solving ... 

Gaussian plume models are easy to use and require relatively few input data. Multiple sources are treated by superimposing the calculated contributions of individual sources. It is possible to include the first-order chemical decay of pollutant species within the Gaussian plume framework. For chemically, meteorologically, or geographically complex situations, however, the Gaussian plume model fails to provide an acceptable solution. 

Petersen, W. B., and Rumsey, E. D., "User s Guide for PAL 2.0—A Gaussian Plume Algorithm for Point, Area, and Line Sources," EPA/600/8-87/009. U.S. Environmental Protection Agency, Research Triangle Park, NC, 1987 (NTIS Accession No. PB87-168 787). 

Pasquill s dispersion parameters were restated in terms of a-y and Cj by Gifford (14, 15) to allow their use in the Gaussian plume equations. The... 

As an example of the use of the Gaussian plume equations using the Pasquill-Gifford dispersion parameters, assume that a source releases 0.37 g s of a pollutant at an effective height of 40 m into the atmosphere with the wind blowing at 2 m s . What is the approximate distance of the maximum concentration, and what is the concentration at this point if the atmosphere is appropriately represented by Pasquill stability class B ... 

Air Pollution Dispersion Application of air dispersion modeling principles and EPA tools to assessing environmental impacts from stack and area releases of pollutants Dispersion theory Gaussian plume model Ground-level concentrations Worst case scenarios Air quality impact assessments Stationary source emissions... 

The earliest and still widely used dispersion model to compute pollutant concentration profiles is the Gaussian plume model for single or multiple source pollution problems. Box-type model techniques, which can take into account nonlinear interactions among different species arising from chemical reactions, have been used in longer-range dispersion computations. 

In Gaussian plume computations the change in wind velocity with height is a function both of the terrain and of the time of day. We model the air flow as turbulent flow, with turbulence represented by eddy motion. The effect of eddy motion is important in diluting concentrations of pollutants. If a parcel of air is displaced from one level to another, it can carry momentum and thermal energy with it. It also carries whatever has been placed in it from pollution sources. Eddies exist in different sizes in the atmosphere, and these turbulent eddies are most effective in dispersing the plume. 

The Gaussian Plume Model is the most well-known and simplest scheme to estimate atmospheric dispersion. This is a mathematical model which has been formulated on the assumption that horizontal advection is balanced by vertical and transverse turbulent diffusion and terms arising from creation of depletion of species i by various internal sources or sinks. In the wind-oriented coordinate system, the conservation of species mass equation takes the following form ... 

Figure 11. Coordinate systems for Gaussian plume model.

Using the Gaussian plume model and the other relations presented, it is possible to compute ground level concentrations C, at any receptor point (Xq, in the region resulting from each of the isolated sources in the emission inventory. Since Equation (2) is linear for zero or linear decay terms, superposition of solutions applies. The concentration distribution is available by computing the values of C, at various receptors and summing over all sources. 

Software for dispersion modeling uses Gaussian plume model. Phe system calculates concentration or deposition values for inputed time periods. May be used in conjunction with "Breeze Air."... 

An alternative simple model for contaminant dilution of rooftop exhaust stacks is presented in Halitsky. This model combines a jet region specification for the upward exhaust movement with a more traditional Gaussian plume region controlled by atmospheric and building-generated turbulent dilution. 

BLP (Buoyant Line and Point Source Dispersion Model) is a Gaussian plume dispersion model associated witli aluminum reduction plants. 

RTDM (Rough Terrain Diffusion Model) is a sequential Gaussian plume model designed to estimate ground-level concentrations in rough (or flat) terrain in die vicinity of one or more co-located point sources. 

The modeling package, delivered to the EPA, includes nationwide data bases for emissions, dispersion meteorology, and population patterns. These data are used as input for a Gaussian plume model for point sources and a box model for urbanwide area sources. Prototype modeling is used for point sources that are too numerous to define individually. Building wake effects and atmospheric chemical decay are addressed. 

Gaussian plume odor impact model, 26 725 Gauss-Markov conditions, 6 39 Gaylusite, 5 785t... 

Problems arise to get informations about the diffusion coeffients Ky and Kz. If equation (3.4) is interpreted as Gaussian distribution, a lot of available dispersion data can be taken into consideration because they are expressed in terms of standard deviations of the concentration distribution. Though there is no theoretical justification the Gaussian plume formula is converted to the K-theory expression by the transformation /11/... 

These are contradictory modifications of the basic assumption the constant diffusivities are now functions of the distance from the emission source and of the stability of the atmosphere. The success in the application of the Gaussian plume model may be justification enough. 

However, we must keep in mind the limitations of this approach, especially the transfer of consistent sets of dispersion parameters to the propagation of air pollution in the vicinity of a source. The Gaussian plume formula should be used only for those downwind distances for which the empirical diffusion coefficients have been determined by standard diffusion experiments. Because we are interested in emissions near ground level and immissions nearby the source, we use those diffusion parameters which are based on the classification of Klug /12/ and Turner /13/. The parameters are expressible as power functions,... 

Fig. 10. Plot of downwind concentration ratio C/CQ against distance C/CQ is calculated by means of the Gaussian plume model with diffusion coefficients after Klug (AK=I,..., V) and Turner (AK=2,..., 5)...

In the special case shown here, the Gaussian plume model does not predict the location of the maximum concentration in agreement with the experiment, but it is appropriate to determine the concentration decay in downwind direction. That what happens between the point source location and the maximum location is of accademic interest only. A... 

This result may also be obtained by starting with Eq. (4.11), assuming a source at z = h and a fictitious source at z = -h, and adding the two expressions in the region 2 > 0. If we assume a totally absorbing earth, the corresponding form of the Gaussian plume equation is... 

The basic Gaussian plume dispersion parameters are ay and a. The essential theoretical result concerning the dependence of these parameters on travel time is for stationary, homogeneous turbulence (Taylor, 1921). Consider marked particles that are released from the origin in a stationary, homogeneous turbulent flow with a mean flow in the x direction. The y component, y, of the position of a fluid particle satisfies the equation... 

Coefficients in Gaussian Plume Dispersion Parameter Correlations"... 

Eq. (9.40) reduces to the Gaussian plume equation. Note that the asymptotic condition in Eq. (9.42) corresponds to zh > point source at or near the ground can also be examined. We can take the limit of Eq. (9.39) as h -> 0 using the asymptotic form of... 

Weber, A. H. (1976). Atmospheric Dispersion Parameters in Gaussian Plume Modeling, EPA-600/4-76-030A. U.S. Environ. Prot. Agency, Washington, D.C. 

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