1 PHOENICS User Conference 2004 Applying CFD to Environmental Flows Eric Jal Connell Wagner, Melbourne, Australia 3-5 May 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 Introduction

3 PHOENICS CFD code has been used TECPLOT used for results visualisation Several 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 Studies

4 City Square - Melbourne, Australia Case 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 Scope

6 Exhaust Discharge : 3m/s Southerly Wind (22 o C Day) City Square - Design Analysis

7 Exhaust Discharge : 3.5m/s Westerly Wind (22 o C Day) City Square - Design Analysis

8 Holdfast Shores - Adelaide, Australia Case Study - Holdfast Shores

9 Multi-use precinct development situated at Glenelg on Adelaides coastal strip Pedestrian comfort and safety concerns on a footbridge due to its 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 Scope

10 Environmental Wind Flow : 9.25m/s Westerly Wind Holdfast Shores - Design Analysis

11 Urban City Planning - Wellington, New Zealand Case 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 Scope

13 Environmental Wind Flow : 21m/s Northerly Wind Urban City Planning - Design Analysis

14 Perisher Valley Resort - NSW, Australia Case Study - Perisher Valley Resort

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 developed The study demonstrated that CFD could be utilised as a practical tool for architectural planning purposes Perisher Valley Resort - Design Scope

16 Environmental Wind Flow : 25km/hr WSW Wind Perisher Valley Resort - Design Analysis

17 City Link Burnley Stack - Melbourne, Australia Case Study - City Link Burnley Stack

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 Scope

19 Stack Exhaust : As Built Configuration City Link Stack - Design Analysis

20 Stack Exhaust : Modified Shaft Geometry Configuration City Link Stack - Design Analysis

21 Fugitive Emissions : Industrial Sand Storage Bins Case 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

23 Presentation End Thank you!

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