The BPIP GEP analysis mode for a specified stack and wind direction is used to quickly identify all the single-tiers and tier-groups that are close enough to influence a stack.
Users can rotate the wind direction using the mouse. While the wind rotates, the following occurs:
1. Anytime the stack is found to be within one or more GEP-SIZs, the single-tier or tier-group that produces the highest GEP value will be displayed and highlighted with a combination of three colors: blue, orange, and yellow. A single-tier will be blue. A tier-group will have a Focal Tier colored blue, a Common Height Tier colored orange, and additional Other Tiers colored yellow. If a tier-group has only a single blue tier with one or more yellow tiers then the Focal Tier is also the Common Height Tier.
2. The associated GEP-SIZ will be displayed in either yellow or blue. Blue if the GEP-SIZ is for a single-tier and yellow if the GEP-SIZ is for a tier-group. Notice that the cross-wind width of the GEP-SIZ is exactly equal to the profile width of the influencing structure (i.e. the single-tier or tier-group). Notice that the length of the GEP-SIZ extends '5L' (where 'L' is the lesser of the influencing structures height or width) past the downwind boundary of the influencing structure.
3. The computed GEP Height will be displayed as a yellow or blue cylinder on top of the Selected Stack cylinder. The GEP Height cylinder will be blue if it is produced by a single-tier and yellow if it is produced by a tier-group.
4. The tiers in a tier-group will move up and down vertically to align their bases with the Focal Tier. This is necessary to demonstrate that BPIP does not use tier elevation values when combining tiers into groups. All tiers are assumed to have the same base elevation as the Focal Tier.
5. Notice he height of the GEP-SIZ block is always equal to the height of the Common Height Tier and that the GEP Height will be "1.5 times the lesser of the GEP-SIZs height or width" above the top of the GEP-SIZ block. This is, in fact, how GEP height is calculated.
The BPIP GEP Max analysis mode is used to display the single-tier or tier-group, with it's corresponding GEP-SIZ and Wind Direction, that produces the maximum GEP height for a Selected Stack.
After selecting a stack with your mouse, the following occurs:
1. The single-tier or tier-group that produces the Maxim GEP Height will be highlighted with a combination of three colors: blue, orange, and yellow. A single-tier will be blue. A tier-group will have a Focal Tier colored blue, a Common Height Tier colored orange, and additional Other Tiers colored yellow. If a tier-group has only a single blue tier with one or more yellow tiers then the Focal Tier is also the Common Height Tier.
2. The associated GEP-SIZ will be displayed in either yellow or blue. Blue if the GEP-SIZ is for a single-tier and yellow if the GEP-SIZ is for a tier-group. Notice that the width of the GEP-SIZ is exactly equal to the profile width of the influencing structure (i.e. the single-tier or tier-group). Notice that the length of the GEP-SIZ extends '5L' (where 'L' is the lesser of the influencing structures height or width) past the downwind boundary of the influencing structure.
3. The computed Maximum GEP Height will be displayed as a red cylinder on top of the Selected Stack cylinder. If the Maximum GEP Height is higher than the Selected Stack, then the stack is too short and will be subjected to downwash effects in the wake of the influencing structure. If the Selected Stack is higher than the Maximum GEP Height, then the stack emissions will be above the influence (i.e. outside the turbulent wake) of the influencing structure.
4. The tiers in a tier-group might have moved up or down vertically to align their bases with the Focal Tier. This is necessary to demonstrate that BPIP does not use tier elevation values when combining tiers into groups. All tiers are assumed to have the same base elevation as the Focal Tier.
5. The height of the GEP-SIZ block is always equal to the height of the Common Height Tier and that the GEP Height will be "1.5 times the lesser of the GEP-SIZs height or width" above the top of the GEP-SIZ block. This is, in fact, how GEP height is calculated.
The BPIP HWE analysis mode is used to display the single-tier or tier-group, with it's corresponding HWE-SIZ, that produces the maximum HWE height for a Selected Stack and a selected Wind Direction. The projected profile dimensions (i.e. height, cross-wind width, down-wind length, and XY offsets) of the single-tier or tier-group that produce each maximum HWE, for each wind direction (36 directions in 10 degree increments), are, in fact, the BPIP output values (i.e. the Build Profile Input Parameters) used by the Prime Plume Rise and Building Downwash Model. See the BPIP Output analysis mode to see exactly what the BPIPs look like for each wind direction around each stack.
The following occurs while rotating the wind direction with the mouse:
1. Anytime the stack is found to be within one or more HWE-SIZs, the single-tier or tier-group that produces the highest HWE value will be displayed and highlighted with a combination of three colors: blue, orange, and yellow. A single-tier will be blue. A tier-group will have a Focal Tier colored blue, a Common Height Tier colored orange, and additional Other Tiers colored yellow. If a tier-group has only a single blue tier with one or more yellow tiers then the Focal Tier is also the Common Height Tier.
2. The associated HWE-SIZ will be displayed in either yellow or blue. Blue if the HWE-SIZ is for a single-tier and yellow if the HWE-SIZ is for a tier-group. Notice that the HWE-SIZ is larger than a GEP-SIZ with a cross-wind width equal to the profile width of the influencing structure (i.e. the single-tier or tier-group) with an additional 1/2L (where 'L' is the lesser of the influencing structures height or width) on both sides. Notice that the length of the HWE-SIZ extends '2L' in front of the upwind boundary of the influencing structure and '5L' past the downwind boundary of the influencing structure.
3. The computed HWE will be displayed as a yellow or blue cylinder on top of the Selected Stack cylinder. The HWE cylinder will be blue if it is produced by a single-tier and yellow if it is produced by a tier-group.
4. The tiers in a tier-group move up and down vertically to align their bases with the Focal Tier. This is necessary to demonstrate that BPIP does not use tier elevation values when combining tiers into groups. All tiers are assumed to have the same base elevation as the Focal Tier.
5. The height of the HWE-SIZ block is always equal to the height of the Common Height Tier and that the HWE will be "1.5 times the lesser of the HWE-SIZs height or the influencing structures across-wind width" above the top of the HWE-SIZ block. This is, in fact, how HWE is calculated.
The BPIP Output analysis mode is used to display the single-tier or tier-group, with it's corresponding BPIPs Box (Building Profile Input Parameters Box including the Common Tier height, cross-wind structure width, along-wind structure length, and XY offsets from the stack XY center) for a Selected Stack and a selected Wind Direction (36 directions in 10 degree increments). The BPIPs box is, in fact, the BPIP output values used by the Prime Plume Rise and Building Downwash Model.
The following occurs while rotating the wind direction with your mouse:
1. The single-tier or tier-group that produces the highest HWE value for the Selected Wind Direction will be displayed and highlighted with a combination of three colors: blue, orange, and yellow. A single-tier will be blue. A tier-group will have a Focal Tier colored blue, a Common Height Tier colored orange, and additional Other Tiers colored yellow. If a tier-group has only a single blue tier with one or more yellow tiers then the Focal Tier is also the Common Height Tier.
2. The associated BPIPs Box, for the Selected Wind Direction, will be displayed in yellow. The BPIPs box is, in fact, the BPIP output values used by the Prime Plume Rise and Building Downwash Model. Notice how the BPIPs Box includes the Common Tier height, cross-wind influencing-structure width, along-wind influencing-structure length, and XY offsets from the stack XY center
3. The height of the BPIPs Box is always equal to the height of the Common Height Tier.
The PRM Plume analysis mode is used to display results produced by the PRIME Plume Rise and Building Downwash Model when running BREEZE AERMOD 6. Observe the downwash plumes that are computed by AERMOD whenever the wind is blowing toward a stack in a direction that has non-zero BPIPs.
To use this analysis mode, first run BREEZE AERMOD with the AERMOD_BREEZE_07026.exe (the 07026 designator might be a larger number as future versions of the executable are released by EPA) model and with the Input Menu | Output Options | Other File & Options | Generate Plume Downwash Centerline File option checked. This tells BREEZE AERMOD to generate an Aermod.prm file in the .amz results archive file. After the AERMOD Model Run, launch Downwash Analyst from the Tools Menu. Both the BPIP input data (i.e. the building and stack geometry) and the Aermod.prm data will be loaded into Downwash Analyst. Note: the PRM Plume analysis mode is made available only when an Aermod.prm file is found in the .amz file.
Select the 'PRM Plume' analysis mode to see the AERMOD computed, downwash-influenced plume geometry with the BPIPs Box (Building Profile Input Parameters Box including the Common Tier height, cross-wind structure width, along-wind structure length, and XY offsets from the stack XY center), the Cavity (i.e. near-wake) Boundary, and the Far-Wake Boundary. View this information in either the 3D Display or the side-view Chart display.
The wind directions for the plume data is not restricted to 10 degree increments. As the Selected Time, and subsequently the wind direction, changes, so does the plume and BPIPs displayed:
1. The plume and wake geometry changes due to changes in the BPIPs geometry and the meteorological conditions.
2. The associated BPIPs Box, for the Selected Time, will shift with the plume direction. The BPIPs box is, in fact, the BPIP values written to the Aermod.prm file by the Prime Plume Rise and Building Downwash Model. Notice how the BPIPs Box will shift slightly from it's original position for Wind Directions that are not increments of 10. This effect is easier to observe using the top-down 2D viewing mode (select '2D' from the display menu or toolbar).