Transcription of Gaussian Plumes from “Point” Sources
{{id}} {{{paragraph}}}
Example: biology
Gaussian Plumes from “Point” Sources
1 GaussianPlumes from Point Sources Time averaged vs instantaneous Plumes Simplified steady-state plume model Eddy diffusion, advection/diffusion equation Gaussian point source plume model plume sigma values vs stability and distance plume reflection Non- Gaussian Plumes plume Rise; plume trajectories Buoyancy-induced dispersion Stack downwashView from below of Coning plume under neutral atmospheric conditionsSource: Slade et al Meteorology and Atomic Energy, 1968 instantaneoustime-averaged2 InstantaneousPlume ShapeTime-averaged plume ShapeFig 4-3, in Martin et alwindDescribing plume Concentrations3 Tim s Simple plume Modelhx123mass/timepassingpoint 1=mass/timepassing thrudisk area 2mass/timepassing thrudisk area 3C1 > C2> C3=Simplified Steady-State plume Model*Pollutant is well mixed and confined within the cone*Pollutant is continuously swept thru the cone by the windConcentration vs. distance downwind depends upon cone shape4()()2disk of areaspeed windrateemission Mass 2at air ofion Concentrat=12 Simple Model #1:()()23mm/sec g/secm g=Disk shape depends upon stability categoryMore unstable and thus more pronounced vertical spreading5 PerspectiveView of Fanning plume in Very Stable AirSource: Slade et al Meteorology and Atomic Energy, 1968 Less verticalmotion6unstableneutralstableAATi me-averaged concentration across AAGaussian (normal) distribution occurs across AA due to changes in wind direction over averaging timeShape is
*Pollutant is continuously swept thru the cone by the wind Concentration vs. distance downwind depends upon cone shape. 4 (wind speed)(area of disk 2) Mass emission rate Concentration of air at 2 = 1 2 Simple Model #1: 3 (m/sec)(m2) ... rate of change in the volume [ = V(δc/δt)] is the change in all three ...
Loading..
Tags:
Information
Domain:
Source:
Link to this page:
Please notify us if you found a problem with this document: