1

PHOENICS User Conference 2004PHOENICS User Conference 2004

“Applying CFD to Environmental Flows”

Eric Jal

Connell Wagner, Melbourne, Australia

3-5 May 2004 - Melbourne, Australia

2

Environmental consequences within the built environment are becoming a crucial issue in engineering project developments

Increasingly common to use CFD in the design process to assess and optimise environmental flow impacts relating to:-• pedestrian comfort and safety• exhaust emissions• airborne dispersion• snow deposition

IntroductionIntroduction

3

PHOENICS CFD code has been usedTECPLOT used for results visualisationSeveral case studies will be presented:-

• City Square - Melbourne, Australia• Holdfast Shores - Adelaide, Australia• Urban City Planning - Wellington, NZ• Perisher Valley Resort - NSW, Australia• City Link Stack - Melbourne, Australia• Holden Sand Bins - Melbourne, Australia

Project Case StudiesProject Case Studies

4

City Square - Melbourne, Australia

Case Study - City SquareCase Study - City Square

5

The Melbourne CBD City Square precinct incorporates an underground car park

Due to architectural constraints the exhaust stack is through a street level cafe

Concerns were raised of the discharge upon café patrons and upon adjacent buildings (hotel with exposed balconies)

CFD study conducted to assess effect of stack discharge for different wind condition

Provide optimised stack solution

City Square - Design ScopeCity Square - Design Scope

6

Exhaust Discharge : 3m/s Southerly Wind (22oC Day)

City Square - Design Analysis City Square - Design Analysis

7

Exhaust Discharge : 3.5m/s Westerly Wind (22oC Day)

City Square - Design Analysis City Square - Design Analysis

8

Holdfast Shores - Adelaide, Australia

Case Study - Holdfast ShoresCase Study - Holdfast Shores

9

Multi-use precinct development situated at Glenelg on Adelaide’s coastal strip

Pedestrian comfort and safety concerns on a footbridge due to it’s position (“wind-gully”)

CFD modelling analysis was conducted

Assessment performed of various proposed ‘wind-break’ structures (with key aesthetic feature must have minimal visual impact)

Holdfast Shores - Design ScopeHoldfast Shores - Design Scope

10

Environmental Wind Flow : 9.25m/s Westerly Wind

Holdfast Shores - Design Holdfast Shores - Design Analysis Analysis

11

Urban City Planning - Wellington, New Zealand

Case Study - Urban City PlanningCase Study - Urban City Planning

12

Pedestrian comfort and safety aspects are a prominent issue for urban city planning

In Wellington specific rules apply as proviso for permitted building developments (over four storeys high)

Property developers and designers must demonstrate no adverse effects on the local wind conditions around the building vicinity

Establish that CFD can be a useful tool

Urban City Planning - Design Urban City Planning - Design ScopeScope

13

Environmental Wind Flow : 21m/s Northerly Wind

Urban City Planning - Design Urban City Planning - Design AnalysisAnalysis

14

Perisher Valley Resort - NSW, Australia

Case Study - Perisher Valley Case Study - Perisher Valley ResortResort

15

Issues were raised during Environmental Impact Statement (EIS) concerning likely snow drifting around redeveloped resort

Two configurations were analysed with CFD to establish snow deposition around the buildings and pedestrian concourse areas

A two-phase CFD model was developedThe study demonstrated that CFD could be

utilised as a practical tool for architectural planning purposes

Perisher Valley Resort - Design Perisher Valley Resort - Design ScopeScope

16

Environmental Wind Flow : 25km/hr WSW Wind

Perisher Valley Resort - Design Perisher Valley Resort - Design AnalysisAnalysis

17

City Link Burnley Stack - Melbourne, Australia

Case Study - City Link Burnley Case Study - City Link Burnley StackStack

18

Emissions from the vent stacks need to be monitored (EPA policy) to ensure pollutant concentrations are within statutory levels

During commissioning it was found that the discharge flow within the exhaust stack was non-uniform and as a consequence the flow could not be sampled and measured

CFD study was undertaken to establish flow characteristics and determine a satisfactory solution to overcome the problem

City Link Burnley Stack - Design City Link Burnley Stack - Design ScopeScope

19

Stack Exhaust : As Built Configuration

City Link Stack - Design AnalysisCity Link Stack - Design Analysis

20

Stack Exhaust : Modified Shaft Geometry Configuration

City Link Stack - Design AnalysisCity Link Stack - Design Analysis

21

Fugitive Emissions : Industrial Sand Storage Bins

Case Study - Fugitive EmissionsCase Study - Fugitive Emissions

22

Project case studies have shown the use of CFD for assessing and optimising solutions related to environmental flows

Issues relating to exhaust emissions, snow deposition, airborne dispersion, pedestrian comfort and safety can be addressed with CFD and can also provide cost benefits

Anticipated that CFD will be a useful tool and essential aid for urban developers, architectural designers and environmental planners for the built environment design

Conclusions Conclusions

23

Presentation End Presentation End

ThankThank youyou!!

24