Odor plume calculation in 6 steps for realtime odor dispersion modeling

Odor plume calculation in 6 steps for realtime odor dispersion modeling

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Odor plume visualization in real-time is the Holy Grail of odor monitoring. Accurate characterization of an odor plume depends on continuous odor monitoring and representative dispersion modeling. Use of real-time odor plume visualization by operators helps them understand how far odors travel in the community, which residence is at risk of being adversely impacted and what actions can be taken to mitigate the potential odor impact before a complaint is received.

In 1 minute and 6 simple steps, we will explain how an odor plume calculation is made OdoWatch.

STEP 1) Define the source

To draw an odor plume we have to know the physical parameters of the source. For releases from stacks or vents, the temperature, flow rate, concentration and exhaust velocity of the gases are needed to calculate the plume. The physical dimensions of nearby buildings can also influence plume dispersion. If the source is an open basin, the length, wide and height are needed.

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STEP 2) Define receptor grid

Receptors are the points where odor plume predictions are made. We delimit a grid of receptor points that covers the area of potential impact. Local land use characteristics and topography are included in the characterization of the receptor grid.

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STEP 3) Capture representative weather conditions

The current weather conditions (wind direction, wind speed, temperature, barometric pressure, solar radiation, etc.) are measured from a meteorological station installed on site. This information determines the direction of the odor plume and mixing of odors in the atmosphere. Odors travel further downwind of the source when mixing is weak (low wind speeds and cool clear nights) and disperse quickly when mixing is strong (high wind speeds and bright sunny days).

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STEP 4) Calculate the odor plume concentrations

For each point of the receptor grid, we calculate the concentration using an atmospheric dispersion model (AERMOD or CALPUFF). The equations takes in account the local weather, distance, source characteristics, topography, land uses and real time concentration measure with Odowatch.

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STEP 5) Interpolate odor plume isoconcentrations

Once the concentration is calculated for all the points of the grid, we interpolate the values and find where in the map are located the zone of same concentrations (isoconcentrations).

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STEP 6) Present the visual odor plume

The OdoWatch software draws the isoconcentrations to visually display the odor plume

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The odor plume visualization is updated every 4 minutes to provide a real-time progression of the odor plume from each monitored source. As shown on the following animation, OdoWatch can to this for several sources simultaneously. Welcome to Dynamic Odor Modeling

Ready to know more about AERMOD Vs. CALPUFF?

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