THEANNALSOFDUNAREADEJOSUNIVERSITYOFGALATIFascicle IX [600397]

THEANNALSOF“DUNAREADEJOS”UNIVERSITYOFGALATIFascicle IX
Metallurgy and Materials Science
ISSN 1453 – 083X1978THE ANNALS OF “DUNAREA DE JOS” UNIVERSITY OF GALATI
FASCICLE IX. METALLURGY AND MAT ERIALS SCIENCE
No. 3– 2015, ISSN 1453 – 083X
ASPECTS REGARDING THE MODELING DISPERSION OF THE
RADIOACTIVE POLLUTANTS AND THE SIMULATION,
FOR GALATI, ROMANIA
Carmen – Penelopi PAPADATU
“Dunarea de Jos” University of Galati-Romania
ABSTRACT
A rail wagon of a train which carrying radioactive material, had leaking
radioactive gas, in the train station Barbosi, on the outskirts of Galati town. This
situation was simulated for a particular wind direction (W-E) and for a specific
speed (35 km/h), making an analyze of the affected areas. It were used models CFD
(Computational Fluid Dynamics) considering 3D terrain model, to find out which
areas are affected. This monitoring is required if it's happened such a disaster, to
decide in what point it is necessary to evacuate the population and to know any
measures to eliminate and to reduce this type of pollution.
KEYWORDS: simulation, modeling, dispersion, radioactive pollutant
1. Introduction
This study was realized during a graduation
project of a student [1] under my direction and it had
good ratings from the part of the exam Commission.
In this project was presented a modelling of
dispersion for the radioactive gas for a region from
Galati, a Romanian town.
It was considered a rail wagon of a train which
carrying radioactive material. This rail wagon had
leaking of gas radioactive in the train station Barbosi,
on the outskirts of Galati town. For this situation, was
made a simulation for a particular wind direction and
for a specific speed, to make an analyze of the
affected areas. In this paper was presented a model
CFD (Computational Fluid Dynamics), considering a
model 3D for the terrain, to find out the affected
areas, for a speed of the wind by approximately 35
km/h .
This monitoring is required. If it's happen such a
disaster, it's necessary to know the results of this
monitoring to know in what point/region it is
necessary to evacuate the population. Population must
know the measures to reduce and to eliminate this
type of pollution, if it is possible [2].
Surface modeling is the process through which
is represented a graphically surface (a surface plot),
natural or artificial, through one or more sub-surfaces
modeled mathematically . To achieve the
experimental program in a paper [1], was made a
simulation for many directions and speeds for the
wind. In this paper was presented a model for onevalue of the speed of the wind. For example, a rail
wagon of a train [2] which carrying radioactive
material, had leaking radioactive pollutants as the gas
form, in the train station Barbosi, on the outskirts of
Galati town. For simulation were used the models
CFD (Computational Fluid Dynamics) considering
3D terrain model, to find out the areas affected.
In figure 1 was presented the location of the
station on the map. It is situated on the outskirts of
Galati town [3].
Fig. 1. Map of the Barbosi station fom Galati
area (drawing parallel lines) [4,8]
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THEANNALSOF“DUNAREADEJOS”UNIVERSITYOFGALATIFascicle IX
Metallurgy and Materials Science
ISSN 1453 – 083X1978THE ANNALS OF “DUNAREA DE JOS” UNIVERSITY OF GALATI
FASCICLE IX. METALLURGY AND MAT ERIALS SCIENCE
No. 3– 2015, ISSN 1453 – 083X
Digital elevation models (MDE) are required in
almost any kind of analysis or modeling of 3D maps.
Applications of mathematical modeling of the earth's
surface and the digital models of the elevation were
basic components within the Geographical
Information Systems (GIS).
Digital Elevation Model (CDM) is the starting
point for calculating the morphometric elements of
the relief, to realize the digital geomorphological map
and for spatial analysis and modeling CFD. After
that, it is possible to solve any practical problem in
the dispersion modeling of the pollutants.
Modeling Earth's surface is a particular case of
surface modeling, which must take into account the
specific problems related to the representation of the
maps in 3D topology to build a certain relief zone.
The terms: ”a digital terrain model- MNT” was
used by Miller and Laflamme. They defined it as ”a
statistical representation of a continuous land surface
using a large number of points whose the horizontal
coordinates (x, y) along the height (z) are known.
This representation is achieved in a coordinate system
arbitrarily. "The models mentioned above refers only
to depictions of the land areas There are numerical
models of height which are known as "Digital Surface
Model (DSM)" or "Digital Feature Heigh Model
(DFHM) "[2].
Remote sensing and aero-photogrammetry tend
to become the main ways of collecting data necessary
to generate elevation MNT (digital terrain model).
These are data acquisition methods which
attempts to minimize data collection effort,
simultaneously with the increase of the accuracy of
the results of the models. They have some
characteristics:
a). Uses satellite imagery and aero-
photogramme;
This technique offers several advantages such
as, for example, can eliminate redundant data when
we have the acquisition of data. Their density can be
adapted to the complexity of the relief zone.
b). Passive sensors are used (photographic
equipment or radiometers) and the images are
obtained with active sensors such as RADAR
systems: Radio Detecting And Ranging and LIDAR:
Light Detection And Ranging.
2. Experimental program and results
In this paper it were used information from [1]
and Google Earth [4], with more slices and
reformation in a CAD program.
Because it is impossible to find the elevation
maps for Galati area, the reconstruction techniques
were used as in the figure 1.
In the figure below, Barbosi station is located
on the outskirts of Galati.For 3D reconstruction of the land, were
respected the following consecutive steps, as shown
in Figure 3. The contour of the elevation for each of
the parallel line was taken from Google Earth and
was introduced in Solid Works. Was scaled the
image and the distance between the successive plans
on which had been situated the image of the elevation
contours. It was rebuilt the surface using specific
features for surfaces from Solid Works.
The reconstructed terrain (3D) was passed to
simulation CFD (Computational Fluid Dynamics)
taking into account the conditions realized by
direction of the wind and the speed of the wind. Plus,
using the functions “particle insertion”, it was
considered a generic gas called fluid flow (wind)
passing over land.
It was considered the speed of the wind
constantly, but the buildings were not considered,
taking into account the fact that the dispersion takes
places on large areas.
In figure 2 were presented the stages of the
reconstruction 3D of the land [1],[2].
Fig. 2. Stages of reconstruction 3D of
the land [2,8]
The elevation contour images were used for 3D
reconstruction of the land (see figure 3).
The built surface which was considered for the
experimental program has 95 km2 and has the urban
buildings. [1,2].
In figure 3 was represented the elevation
contour for the reconstruction 3D of the land.
In figure 4 was represented the reconstruction of
the land using succession plans with the elevation
plans [1].
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THEANNALSOF“DUNAREADEJOS”UNIVERSITYOFGALATIFascicle IX
Metallurgy and Materials Science
ISSN 1453 – 083X1978THE ANNALS OF “DUNAREA DE JOS” UNIVERSITY OF GALATI
FASCICLE IX. METALLURGY AND MAT ERIALS SCIENCE
No. 3– 2015, ISSN 1453 – 083X
For example, it were considered the speed of the
wind v = 35 km/h and the direction of the wind was
W-E.The emission of the gas was up to 3 kg/s from
the rail of the train which transport the radioactivepollutant. It was considered the pressure of 760
mmHg. In this situation, the wind flow and the
modeling 3D of the land are presented in figure 8 [1].
Fig. 3. The elevation contour for the reconstruction 3D of the land
Fig. 4. The reconstruction of the land – usesuccession plans with the elevation plans
(Modeling 3D of the land) [1,8]
In particular we see a variation of the
pressure depending on the land elevation, which leads
to fact that the dispersion is not constantly and
depend on the topology of the land [8].There are variations of the speed of air
masses because of the terrain height variation, as
shown in Figure 6 [1].
In figure 5 was presented the trajectory of
the gas emitted (image 1), [1,2].
Fig. 5. The trajectory of the gas emitted (image 1)
Because of the speed of the wind, the dispersion
was realized on a short distance. In figures 6 and 7
were presented the wind flow at 35 km/h. In figure 8
was presented the affected area, around Galati town,from Romania. After simulations, the direction of the
pollutants dispersion is similarly with the situation
presented in figure 8.
– 63 –

THEANNALSOF“DUNAREADEJOS”UNIVERSITYOFGALATIFascicle IX
Metallurgy and Materials Science
ISSN 1453 – 083X1978THE ANNALS OF “DUNAREA DE JOS” UNIVERSITY OF GALATI
FASCICLE IX. METALLURGY AND MAT ERIALS SCIENCE
No. 3– 2015, ISSN 1453 – 083X
Fig. 6. The wind flow (35 Km/h)– looked up, [1]
Fig. 7. The wind flow (35 Km/h)– viewed from the side,[1]
Fig. 8. The affected area
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THEANNALSOF“DUNAREADEJOS”UNIVERSITYOFGALATIFascicle IX
Metallurgy and Materials Science
ISSN 1453 – 083X1978THE ANNALS OF “DUNAREA DE JOS” UNIVERSITY OF GALATI
FASCICLE IX. METALLURGY AND MAT ERIALS SCIENCE
No. 3– 2015, ISSN 1453 – 083X
The area marked with a red color must be
evacuated. In figure 9 is represented the geographical
surface which was analyzed, taking into account 95
km2surface. Figure 10 presents the variation of
pressure in the perpendicular plan on the emission
point.
Fig. 9.The geographical surface which was
analyzed, taking into account 95 km2surface
Fig. 10. The variation of the pressure in the
perpendicular plan on the emission point
(image 1), [1]3.Conclusions
As shown in Figure 8 the affected area will be
around the gas dispersion path. For this area should
be taken measures to prevent and mitigate the effects
of disaster. Population from this area must be
evacuated because the constant direction of the wind
which is the same for all the time, during of the
disaster. The evacuation must be made by authorities,
avoiding the area indicated.
Aknowlegement
The experimental study was realized with Bucur
A.- a student from Faculty of Engineering.
References
[1]. Bucur, A .-« Studii și cercetări privind monitorizarea și
impactul radioactivității asupra mediului în regiunea Galați-
Brăila», Lucrare de licență, Universitatea « Dunarea de Jos » din
Galati, Coordonator științific: Dr.ing.ec. Papadatu Carmen, 2014;
[2]. Papadatu, C.P. –«Study regarding the dispersion modeling of
the radioactive pollutants and the simulation in this case “,Journal
of Multidisciplinary Engineering Science, 2015, pag.2500-2508,
ISSN 3159-0040,Germany;
[3].http://apmgl.anpm.ro ;
[4].https://earth .google .com ;
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