lib.atmosphere module

lib.atmosphere.Gaussian(y, z, h, Q, u, Sy, Sz)[source]

This function evaluate the Gaussian dispersion model for air dispersion of contaminants

Parameters:
yfloat

Crosswind distance from the plume axis [m]

zfloat

Vertical distance from the surface [m]

hfloat

effective source height [m]

Qfloat

Emmision rate [g/s]

ufloat

Wind speed in the x direction [m/s]

Syfloat

Dispersion parameter in the horizontal direction [m]

Szfloat

Dispersion parameter in the vertical direction [m]

Returns:
cfloat

Concentration of contaminants at a given point [g/m³]

References

[1] de Visscher, A.; Air Dispersion Modeling: Foundations and Applications. John Wiley & Sons, 2014

Examples

Example 2.1.

>>> Sy, Sz = BriggsDispersion(1500, 'D')
>>> "%0.3e" % Gaussian(0, 0, 90, 100, 7, Sy, Sz)
'1.603e-04'
>>> "%0.3e" % Gaussian(100, 0, 90, 100, 7, Sy, Sz)
'1.075e-04'
lib.atmosphere.Pasquill_Gifford_Stability(u, day=True, solar=60, cloudiness=0.5)[source]

This function evaluate the Pasquill-Gifford stability class

Parameters:
ufloat

Wind speed in the x direction measured at 10m height [m/s]

dayboolean

Boolean to specify day or night

solarfloat, optional

Sun inclination above the horizon [º] Range between 0 (sunrise) and 90º (mediodía) Neccesary only is day is True

cloudinessfloat, optional

Cloud cover in sky in range 0…1 [-] Neccesary only is day is False

Returns:
class_string
Pasquill-Gifford stability class name

A : Very unstable B : Moderately unstable C : Slightly unstable D : Neutral E : Stable

References

[1] de Visscher, A.; Air Dispersion Modeling: Foundations and Applications. John Wiley & Sons, 2014

lib.atmosphere.BriggsDispersion(x, class_, urban=False)[source]

This function evaluate the dispersion parameters

Parameters:
xfloat

Distance to the source [m]

class_string

Pasquill-Gifford stability class name Accept to mixed classes as AB for intermediate class

urbanBoolean

Boolean to specify urban terrain

Returns:
Syfloat

Dispersion parameter in the horizontal direction [m]

Szfloat

Dispersion parameter in the vertical direction [m]

References

[1] de Visscher, A.; Air Dispersion Modeling: Foundations and Applications. John Wiley & Sons, 2014

Examples

Example 2.1.

>>> "%0.1f, %0.1f" %BriggsDispersion(1500, 'D')
'111.9, 49.9'

References