BREEZE Software

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BREEZE Downwash Analyst and

3D AERMOD Plumes Using

BREEZE AERMOD with 3D Analyst

Downwash Analyst

Downwash Analyst

Objectives:1. General Introduction to BREEZE Downwash Analyst (DWA)

2. Demonstrate DWA’s BPIP Analysis Modes.

3. Demonstrate DWA’s PRIME Plume Mode.

4. Demonstrate how BREEZE AERMOD 6 and BREEZE 3D Analyst can be used to display hourly AERMOD plumes.

5. Demonstrate, three dimensionally, how building profiles influence AERMOD plumes.

BREEZE Downwash Analyst

Downwash Analyst

Objective #1General Introduction to BREEZE Downwash Analyst

• History… DWA now “removes the mystery of BPIP”.

• Display PRIME plume geometry.

• Downwash, BPIP, or Building Profile Analyst?

• Simple ‘visualization tool’… nothing to enter or edit… just observe.

• Understanding what you see is the hard part.

Downwash Analyst

What is BPIP? What does it do?

BPIP Does Two Things:

1. Computes the maximum Good Engineering Practice (GEP) height for all stacks influence by one or more buildings.

2. Computes the Building Profile Input Parameters (BPIPs) for 36 wind directions around each stack.

What is BPIPPRM? What’s the difference?

BPIPPRM is the ‘PRIME’ version of BPIP that includes the X,Y position of building profiles, relative to point sources (i.e. stacks).

Downwash Analyst

BPIP Acronyms….

BPIP – Build Profile Input Program

BPIPPRM – PRIME version of BPIP

PRIME – Plume Rise Model Enhancement (includes X,Y values)

GEP – Good Engineering Practice stack height

SIZ – Structure Influence Zone

L – min(W, H), minimum Width or Height of a SIZ

GEP SIZ – SIZ used to locate stacks for GEP calculations

HWE – Height of Wake Effect (same equation as GEP, larger SIZ)

HWE SIZ – SIZ used to locate stacks for HWE/BPIPs calculations

BPIPs – Building Profile Input Parameters

Downwash Analyst

How to launch BREEZE Downwash Analyst

1. From BREEZE AERMOD 6a. Open project file.b. Select ‘Downwash Analyst’ from

Tool Menu.Note: If an .amz file exists and contains an Aermod.prm

file, the .prm file will also be loaded.Note: This will load the stack and building geometry

contained in the AERMOD input file (i.e. the .amifile).

2. From Downwash.exea. Open BREEZE .amz file

containing ‘Bpip Input File’ and/or ‘Aermod.prm’ file.

b. Open EPA BPIP files with .inp or .bpi extension.

c. Open BREEZE .prm files.Note: This will load the stack and building geometry

contained in the ‘Bpip Input File’ (i.e. the file generated and saved to the .amz file when ‘BPIP Model Run’ was last executed from within BREEZE AERMOD 6.)

Downwash Analyst

BREEZE Downwash Analyst’s Layout

Downwash Analyst

Objective #2Demonstrate BREEZE Downwash Analyst’s BPIP Analysis Modes.

5L 5L

1/2L

1/2L

2L

Downwash Analyst

DWA’s Four BPIP Analysis Modes:Two Things… for Each of BPIP’s Two Things…

1. Compute the maximum GEP height for all stacks influenced by one or more buildings.

1. BPIP GEP - Show the GEP (a measure of how much buildings influence a stack) for all wind directions. Only stacks within a GEP SIZ will produce a GEP value.

2. BPIP GEP Max - Show the single wind direction and corresponding tier(s) that have the maximum influence on a stack.

2. Compute the Building Profile Input Parameters (BPIPs) for 36 wind directions around each stack.

3. BPIP HWE - Show how stacks are located within the HWE SIZ of buildings for each wind direction.

4. BPIP Output - Show the final BPIPs for each wind direction.

Downwash Analyst

1. BPIP GEP - Select Stack & Wind Direction - Display the single-tier or tier-group, with it's GEP-SIZ, that produces the maximum GEP stack height for a selected stack and a selected wind direction.

2. BPIP GEP Max - Select Stack - Display the single-tier or tier-group, with it's GEP-SIZ, and the single wind direction that produces the maximum GEP height for a selected stack.

3. BPIP HWE - Select Stack & Wind Direction - Displays the single-tier or tier-group, with it's HWE-SIZ, that produces the maximum HWE for a selected stack and a selected wind direction.

4. BPIP Output - Select Stack & Wind Direction - Display the single-tier or tier-group that produces the maximum HWE and it's corresponding BPIPs (i.e. Building Profile Input Parameters including height, width, length, and X,Y offsets) for a selected stack and a selected wind direction.

BPIP Analysis Modes

Downwash Analyst

DWA – Analysis Mode #1

BPIP GEP - Select Stack & Wind Direction

Downwash Analyst

BPIP GEP - Select Stack & Wind DirectionDisplay the single-tier or tier-group, with it's GEP-SIZ, that produces the

maximum GEP stack height for a selected stack and a selected wind direction.

Downwash Analyst

GEP Calculation for Selected Stack and Selected Wind Direction

Wp

Hcht

GEP SIZ

GEP for selected wind direction

Max GEP for selected stack (produced from other wind direction)

1.5L

GEP = Good Engineering Practice stack height

Eft = Elevation of Focal Tier

Es = Elevation of Stack

Hcht = Height of Common Height Tier

Wp = Projected Width of single tier or tier group

L = min(Wp, Hcht)

Tier Group

GEP =(Eft – Es) + Hcht + min(Wp, Hcht) x 1.5

Focal Tier and Common Height Tier

5L

Downwash Analyst

Squat TierW = 15, L = 15, H = 5

GEP = H x 2.5

Cube TierW = 10, L = 10, H = 10

GEP = H x 2.5

GEP for Squat and Cube Tiers….GEP =(Eft – Es) + Hcht + min(Wp, Hcht) x 1.5

Downwash Analyst

GEP for Tall Tiers….GEP =(Eft – Es) + Hcht + min(Wp, Hcht) x 1.5

Tall TierW = 5, L = 5, H = 10

GEP = H + (Wp x 1.5)

Downwash Analyst

GEP for Tall-Long Tiers….GEP =(Eft – Es) + Hcht + min(Wp, Hcht) x 1.5

Tall-Long TierW = 5, L = 10, H = 10

GEP = H + (Wp x 1.5) or GEP = H x 2.5

Downwash Analyst

Tall Round TierD = 5, H = 10

GEP = H + (D x 1.5)

GEP for Round Tiers….GEP =(Eft – Es) + Hcht + min(Wp, Hcht) x 1.5

Squat Round TierD = 10, H = 10GEP = H x 2.5

Downwash Analyst

Two TiersW = 5, L = 5, H = 10

Separation = 6GEP = 0 GEP = H + (Wp x 1.5)

Blue SIZ when produced by single tier.

GEP for Tier Groups… The Complex Part of BPIP

GEP = H x 2.5

Yellow SIZ when produced by tier group.

Tiers can combine when the projected width of

both tiers is greater than the minimum distance

between the tiers.

Downwash Analyst

Two TiersW = 5, L = 5, H = 10

Separation = 8

Two tiers with minimum separation distance greater than either tiers maximum projected width will never be combined….

GEP = H + (Wp x 1.5)

Downwash Analyst

Two TiersW1 = 5, L1 = 5, H1 = 7.5W2 = 5, L2 = 5, H2 = 10

Separation = 6

GEP = 7.5 + (5.5 x 1.5) = 15.75

GEP = 7.5 + (7.5 x 1.5) = 18.75GEP = 10 + (7.0 x 1.5) = 20.5

GEP = 0

Group has larger GEP

Single tier has larger GEP

Wp < SeparationStack not in GEP SIZ

Two tiers with different heights….

Downwash Analyst

Three TiersW1 = 4, L1 = 4, H1 = 4W2 = 4, L2 = 4, H2 = 5 W3 = 4, L3 = 4, H3 = 6

Separation = 1

Three medium-height tiers with different heights….

GEP = 6 + (4.5 x 1.5) = 12.75

Single tier has larger GEP

GEP = 5 + (5.0 x 1.5) = 12.5

GEP = 4 + (4 x 1.5) = 10

Not in GEP Sizof shortest tier

GEP = 4 + (4 x 1.5) = 10

Group does not produce larger GEP

Group has larger GEP

Downwash Analyst

GEP = 7 + (7 x 1.5) = 17.5

Three tall tiers with different heights….

Three TiersW1 = 2, L1 = 2, H1 = 7W2 = 2, L2 = 2, H2 = 8 W3 = 2, L3 = 2, H3 = 9

Separation = 1

All other group tiers (yellow)Focal tier (blue)

Common height tier (orange)

Downwash Analyst

Three TiersW1 = 2, L1 = 2, H1 = 7W2 = 2, L2 = 2, H2 = 10 W3 = 2, L3 = 2, H3 = 11

Separation = 1

GEP = 7 + (7 x 1.5) = 17.5

Two of the three tiers taller….

GEP = 10 + (5.5 x 1.5) = 18.25

DWA can toggle between 3D view and top-down view.

Downwash Analyst

Three TiersW1 = 2, L1 = 2, H1 = 7, E1 = 2W2 = 2, L2 = 2, H2 = 10, E2 = 0 W3 = 2, L3 = 2, H3 = 11, E3 = 0

BPIP assumes that all tiers in a group have the same elevation as the focal tier.

GEP = 7 + (7 x 1.5) = 17.5

DWA shows this effect by moving the base of all tiers in a group to the focal tiers elevation.

GEP = 10 + (5.5 x 1.5) = 18.25

Varying Tier Elevations… what does BPIP do?

Downwash Analyst

GEP = 10 + (5.5 x 1.5) = 18.25

Varying Tier Elevations… what does BPIP do?

Three TiersW1 = 2, L1 = 2, H1 = 7, E1 = 0W2 = 2, L2 = 2, H2 = 10, E2 = 0 W3 = 2, L3 = 2, H3 = 11, E3 = 0

Three TiersW1 = 2, L1 = 2, H1 = 7, E1 = 0W2 = 2, L2 = 2, H2 = 10, E2 = 0 W3 = 2, L3 = 2, H3 = 5, E3 = 6

GEP = 11 + (5.5 x 1.5) = 19.25

Downwash Analyst

Three Overlapping TiersW1 = 8, L1 = 2, H1 = 7W2 = 5, L2 = 2, H2 = 10 W3 = 2, L3 = 2, H3 = 11

Separation = 1

Overlapping Tiers? Are they allowed?

GEP = 10 + (5.5 x 1.5) = 18.25GEP = 7 + (7 x 1.5) = 17.5 GEP = 10 + (5 x 1.5) = 17.5

Downwash Analyst

Stacked tiers? An obvious mistake…

GEP = 4 + (4 x 1.5) = 17.5

Three Stacked TiersW1 = 8, L1 = 2, H1 = 7, E1 = 0W2 = 5, L2 = 2, H2 = 3, E2 = 3 W3 = 2, L3 = 2, H3 = 1, E3 = 1

Tier elevations should always be ground level…never the roof-top elevation of another tier.

GEP = 7 + (7 x 1.5) = 17.5

Downwash Analyst

Multi-Tier Buildings… prevent tier grouping…

EPA Example A5ST - Three multi-tier buildings containing three tiers each.

What does this accomplish?

1. Changes the BPIPs? YES…but why?

2. Prevents stacked tiers (i.e. a single elevation value is assigned to all tiers in a multi-tier building).

No other tiers in the building containing the Focal Tier will be part of a Tier Group.

Downwash Analyst

Stack elevation… how does it affect GEP?

Stack elevation will shift the GEP values. However, the relative elevation of a stack to tiers will not affect tier associations to the stack. Only changes relative tier-to-tier elevations will affect the association of tiers to stacks.

Downwash Analyst

DWA – Analysis Mode #2

BPIP GEP Max - Select Stack

Downwash Analyst

BPIP GEP Max - Select StackDisplay the single-tier or tier-group, with it's GEP-SIZ, and the single wind

direction that produces the maximum GEP height for a selected stack.

Downwash Analyst

BPIP GEP Max - Select Stack

Select a stack to see the wind direction and single-tier or tier-group that most influences (i.e. produces the highest GEP for) the stack.

BPIP locates all stacks within GEP SIZs and

computes a GEP value for 1440 (360 x 4) wind directions around each

stack.

Downwash Analyst

DWA – Analysis Mode #3

BPIP HWE - Select Stack & Wind Direction

Downwash Analyst

BPIP HWE - Select Stack & Wind DirectionDisplays the single-tier or tier-group, with it's HWE-SIZ, that produces the maximum HWE for a selected stack and a selected wind direction.

Downwash Analyst

HWE Calculation for Selected Stack and Selected Wind DirectionHWE =(Eft – Es) + Hcht + min(Wp, Hcht) x 1.5

HWE = Height of wake effect

Eft = Elevation of Focal Tier

Es = Elevation of Stack

Hcht = Height of Common Height Tier

Wp = Projected Width (single tier or tier group)

L = min(Wp, Hcht)

5L

1/2L

1/2L

2L

WpHcht

HWE SIZ

5L

HWE for selected wind direction

1.5L

Tier Group

Common Height Tier

Focal Tier

Downwash Analyst

DWA –Analysis Mode #4

BPIP Output - Select Stack & Wind Direction

Downwash Analyst

BPIP Output - Select Stack & Wind DirectionDisplay the single-tier or tier-group that produces the maximum HWE and it's

corresponding BPIPs (i.e. Building Profile Input Parameters including height, width, length, and X,Y offsets) for a selected stack and a selected wind direction.

Downwash Analyst

Wind Dir = 210

Wind Dir = 200

Wind Dir = 190

Wind Dir = 180

Wind Dir = 170

Wind Dir = 160

Wind Dir = 150

BPIPs for 36 Wind Directions Around a Stack… produced by either a Single-Tier or a Tier Group…

Downwash Analyst

BPIPs do NOT have an elevation… the projected height is relative to the stack elevation…

All stacks and tiers are moved to zero elevation in ‘BPIP Output’ Mode

Downwash Analyst

Pick a stack and rotate the wind direction to view all the

BPIPs.

BPIP Output - Select Stack & Wind Direction

Downwash Analyst

DWA –Analysis Mode #5PRM Plume - Select Stack

3D Display

Objective #3

Downwash Analyst

DWA –Analysis Mode #5

PRM Plume - Select Stack

Side-View Chart

Downwash Analyst

Select ‘Downwash plume centerline file’ in the BREEZE AERMOD 6 Output / Options dialog….

Downwash Analyst

Variation of PRIME plume and near/far wake boundaries with increasing wind speed…

1.5 m/s

2.5 m/s

3.5 m/s

4.5 m/s

Downwash Analyst

Variation of PRIME plume and near/far wake boundaries with varying wind direction…

Wind Dir = 70

Wind Dir = 80 Wind Dir = 110

Wind Dir = 100

AERMOD 6 with 3D Analyst

Demonstrate how BREEZE AERMOD and BREEZE 3D Analyst can be used to display 3D plumes.

Objective #4

Select ‘1 hr’ post file from the Output / Post Files dialog…

A 2km x 2km x 200m grid with 50m XY spacing and

10m Z spacing

AERMOD 6 with 3D Analyst

Select ‘1 hr’ post file from the Output / Post Files dialog…

AERMOD 6 with 3D Analyst

Load the post file into BREEZE 3D Analyst…

Select a time and display Volume rendering with XY,

XZ, YZ contour planes

Turn off the bounding box, reduce the contour’s

FillOpacity, and reduce ElevationScale

Set the Volume properties as shown above… see User’s Guide for details

about each setting

AERMOD 6 with 3D Analyst

Select an appropriate set of ‘User Defined’ levels…

AERMOD 6 with 3D Analyst

Save all 3D window settings using the File / Templates / Load & Save options….

AERMOD 6 with 3D Analyst

First look at the plume of a single stack with no buildings and increasing wind speed in one direction…

AERMOD 6 with 3D Analyst

0.5 m/s

1.0 m/s

1.5 m/s

2.0 m/s

4.0 m/s

8.0 m/s

12.0 m/s

16.0 m/s

AERMOD 6 with 3D Analyst

Demonstrate how building profiles influence AERMOD plumes.

Objective #5

Without Building

Squat Building

Tall Building

AERMOD 6 with 3D Analyst

With Building30x30x15mWithout

Building

1.0 m/s

1.5 m/s

2.0 m/s

AERMOD 6 with 3D Analyst

16.0 m/s

12.0 m/s

8.0 m/s

4.0 m/s

AERMOD 6 with 3D Analyst

Without Building

1.0 m/s

1.5 m/s

2.0 m/s

With Building30x30x30m

AERMOD 6 with 3D Analyst

16.0 m/s

12.0 m/s

8.0 m/s

4.0 m/s

AERMOD 6 with 3D Analyst

Use 3D Analyst’s Tools / Merge Data / Difference to compute the 3D difference of a plume with and without a building…

AERMOD 6 with 3D Analyst

1.0 m/s

2.0 m/s

3.0 m/s

4.0 m/s

5.0 m/s

6.0 m/s

8.0 m/s

12.0 m/s

Plume with Building – Plume without Building =

AERMOD 6 with 3D Analyst

Downwash Analyst, AERMOD 6, 3D Analyst

Conclusions…

1. BREEZE Downwash Analyst provides a means to examine the interactions between buildings and stacks.

2. DWA provides a detailed display of how BPIP computes GEP values and BPIPs for each stack.

3. DWA provides a quick easy way to determine the conditions that produce the maximum GEP for a stack.

4. DWA provides a quick easy way to inspect and verify building models.

5. DWA provides a means to view the BPIPs and their associated tiers for each stack.

6. AERMOD plumes can be examined three dimensionally using BREEZE AERMOD 6’s 3D Receptor Grids and BREEZE 3D Analyst’s Volume Rendering functions.