Gaussian Plume Atmospheric Dispersion Model

Stack & Emission

Stack height i 50 m

Stack diameter i 2.0 m

Exit velocity i 15.0 m/s

Exit gas temperature i 400 K

Ambient air temperature i 293 K

Emission rate Q i 50 g/s

Molecular weight i 64 g/mol

Atmosphere

Wind speed (at stack height) i 5.0 m/s

Atmospheric stability class i

Dispersion coefficient set i

Plume Rise (Briggs)

Buoyancy flux F

— m⁴/s³

Momentum flux F_m

— m⁴/s²

Rise ΔH

— m

Effective H

— m

Rise regime

—

Peak ground-level conc. (centerline)

— µg/m³ @ x = — m

Concentration Query

Click a rendered point in the plume to sample it, or enter coordinates manually (x downwind, y crosswind, z height, all in m).

x (m)

y (m)

z (m)

3D Plume Field drag: rotate · scroll: zoom · right-drag: pan

Building concentration field…

CONC. (µg/m³)

————0

Governing Equation

Steady-state Gaussian plume with total reflection at the ground (z=0). Source: Turner, D.B. (1994) Workbook of Atmospheric Dispersion Estimates, 2nd ed., CRC Press, Eq. 2-2; US EPA 40 CFR Part 51 App. W.

Current parameters

Q = — g/s u = — m/s H = — m

PPM Conversion (Ideal Gas Law)

Molar volume V_m = RT/P is evaluated at the current ambient temperature and 1 atm, not the fixed 24.45 L/mol constant (which only holds at exactly 25°C / 298.15 K).

V_m(T_a) = — m³/mol (= — L/mol)