Using for Pollutant Dispersion

Andrea Vignaroli – University of Perugia

UNIVERSITA’ DEGLI STUDI DI PERUGIA

Facoltà di Ingegneria

Dipartimento di Ingegneria Industriale

In collaboration with…

Vector AS

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The aims of this work…The aims of this work…

- To develop hidden potentialities of Windsim

- To put the basis for the realization of a new commercial software

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Foreseing pollutant emissions can be important to…

•interpretate data measured by the interest area monitoring web

•necessary for the Valuation of Environmental Impact of future factories or infrastructure

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Applicabilty Fields

•Spatial Scale: local and meso scale;•Territory type: every kind of site (complex terrain)•Time Scale: every kind of period (from 1 hr to a year)•Source type: every kind source that can be discretized with an emission point•Pollutant type: gas, smells & particles

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Dispersion Modelling on PHOENICS

Two approaches for Two different tipology of pollutants:

• GENTRA PARTICLES

• PASSIVE DISPERSION GAS & SMELLS

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- GENTRA -

stochastic particle dispersion model for

turbulent flow

Gentra integrates the particle equations in a

Lagrangian frame while Phoenics solves the

equations governing the continuous phase in the

normal manner

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- GENTRA -

Particle Dispersion (Gentra) Data Input:

• X, Y , Z local position [m];• u, v, w inlet velocity vectors [m/s];• Flux rate in [Kg/s];• Density [Kg/m^3];• Particle diameter [m];• Number of particles to be simulated;

every particle will bring with itself a fraction of the given emission rate

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- GENTRA -

Concentration map

Amount of particles in each cell

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- GENTRA -

Results for 240°-sector simulation

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- Passive Dispersion -

“PASSIVE” means…

Determining the flow field in the classical way

Introducing in the q1 file a new inlet for the pollutant (Gas or smell)

New simulation using the previous run as input to the dermine how the new phase is dragged by the wind

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- Passive Dispersion -

Passive Dispersion Data Input :

• X , Y , Z position in cell numbers;• Flux rate in [Kg/s];• Area of Chimney final section [m];• Temperature [°C];• Density [Kg/m^3];

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- Passive Dispersion -

Results for 240°-sector simulation

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OUTPUT DATA

Strictly Correlated to what the enviromental laws prescribe

Importants Outputs are…• concentration map of short term simulation for a given wind speed and direction• 3D visualization of the concentration field using isosurfaces • concentration map of a long term simulation for a given one – year - climatology

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- Output Data -

12 sectors climatology

12 Averaged speeds over boundary layer

12 Phoenics runs with different input

For long term simulation the climatology influeces the windfield module

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- Output Data -

One-year-averaged concentration map

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…WORK IN PROGRESS

Something for the future…

• validate the model with measured data

• prescribed pollutant limit as input in order to have percentiles, and map with over valued concentration points

• 24 sectors climatology for smoother maps

• linear and volume sources

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