Advanced and Robust Analysis of Wind Effects
Advanced and Robust Analysis of Wind Effects
Air quality and pollution dispersion studies are undertaken to investigate the dispersion of exhaust gases from proposed or existing developments or nearby high density use roadways. This type of study is particularly important should the exhaust gases be harmful to pedestrians or occupants of the proposed development. They can also be used to investigate whether exhaust gases are likely to recirculate into any of the developments outdoor areas or fresh air-intakes of if they are likely to generate any undesirable effects.
Windtech are able to offer both flow visualisation and spectrometry techniques, to assist in understanding the dispersion patterns of the gases and to accurately measure their concentrations. The spectrometry technique can further provide detailed information on the expected concentration levels of any exhaust gases at the impact zones, which can be compared to relevant exposure standards.
Below are sample case studies where Windtech has recently undertaken wind tunnel modelling for air quality assessments:
Fort Cambridge, Malta
This study investigated the impact of the proposed Fort Cambridge development on the natural dispersion of vehicle exhausts from the 3 most heavily used road intersections in the area. Flow visualisation was undertaken to identify critical wind directions for use in spectroscopic assessment of the levels of NO2 and PM10 at the development location.
This allowed a comparison to both existing site conditions and the annual, daily and hourly standards. It was found that the inclusion of the development had minimal impact on the air quality adjacent to and surrounding the development.
Hallets Point Buildings 6 & 7, Queens, New York
This project involved the modelling of gas dispersion from an existing boiler stack located between Buildings 6 & 7 of a proposed development at Hallets Point, New York. Flow visualisation techniques were used to assess the impact on the buildings on the dispersion patterns for different wind directions. It was found that the exhaust gases intermittently impacted the proposed buildings as well as certain ground level pedestrian trafficable areas. The analysis was also able to review the impact of various exhaust speeds to indicate which scenario provided the most beneficial outcomes.
The next phase involved accurate, quantitative assessment of the exhaust concentrations against New York City criteria. Recommendations included replacement of the existing boiler appliance with a new appliance that would emit significantly lower concentrations of NOx gases.
Windtech can undertake Air Quality studies using either a physical scale models or Computational Fluid Dynamics (CFD). Common applications of this type of study include:
The re-entry of air-conditioning exhaust into the system, potentially leading to the fatal Legionnaires disease.
For more information, or if you would like to discuss a current project please email us at reception@windtechglobal.com
Wynyard Walk was announced on August 15, 2018 as the winner of the Engineering Excellence awards by Engineers Australia for the Infrastructure Category.
Windtech consultants assisted the contractor Theiss, architects Woods Bagot and structural consultants Taylor Thomson Whitting as the wind engineering consultant on this complex transport development and major pedestrian infrastruture, serving 33,000 pedestrians daily.
This project connects the existing Wynyard Train Station to the new Barangaroo waterfront precinct via a new civic entry building for Wynyard Station, a pedestrian tunnel, a western tunnel portal, a plaza and a bridge spanning Sussex Street.
Windtech assisted with the following studies:
The Engineers Australia award comes on top of the following awards:
The costs of remedial work to address wind noise issues is often quite high, especially when compared to the cost of engaging Windtech Consultants to undertake a desktop wind-induced noise assessment. Façade elements are a common source of wind noise in buildings. Engaging Windtech Consultants at the outset, before the façade elements are fabricated, can avoid very costly rectification work to mitigate wind noise issues in buildings.
Windtech have undertaken substantial internal research on this topic since the mid-1990’s and have completed over 100 investigations since that time. These include a significant number of remedial studies. Our ability to identify problems and cost effective solutions quickly is a direct reflection of our experience.
An example of one such remedial wind-induced noise study was wind-induced noise and vibrations on the horizontal aluminium circular hollow section (CHS) sunshades situated along the top of the façade of the Workzone Building located at 202 Pier Street, Perth (pictured above). Structures such as these have been reported to exhibit large wind induced excitation. These have been due to both vortex-induced excitation and wake interference excitation mechanisms. Structures such as this will be particularly susceptible if they have either low damping or low mass. After testing the sample in the wind-tunnel it was determined that the CHS members were mainly influenced by the resonant response to the vortex shedding frequency.
Several treatment options were proposed including mounting the louvres on rubber connector rings, removing every second circular member from the sample, and having expanding foam inserted to various circular members. Of these the adopted solution was to insert expanding foam into the first and seventh members. The hardened expanding foam within the circular members resulted in a reduction of the natural frequency (which lowered the critical velocity) as well as providing additional damping and mass.
Another example of a remedial wind-induced noise study recently undertaken by Windtech is in relation to the perforated metal screens on the Northern Beaches Hospital Carpark façade (7 storeys – 99m x 33.8m x 23.25m). These punched metal screens tended to generate extremely loud (up to 115dB) high pitch wind noise. Windtech proposed alternative treatment strategies to mitigate the wind noise from the screens. The performance of these was verified through testing in one of our three wind tunnels – first to replicate the on-site conditions then with the effect of the treatment. Two treatment strategies were tested:
The expanded metal screens were most effective in completely eliminating the harmonics between the vortices shed behind the original screens. The punched metal screens with a randomised pattern was also effective for most of the cases and generated a low amplitude noise for one angle of attack in high wind.
Windtech regularly undertakes remedial wind-noise studies due to our demonstrated depth of experience in this field. This enables us to formulate practical solutions at the outset. We recommend a desktop wind noise assessment prior to fabrication to avoid the cost of remediation. If you would like to discuss your current project or have a wind noise problem, please contact one of the following Windtech staff who can provide expert advice in this field:
Dr Nicholas Truong: nicholas@windtechglobal.com
Simon Ronald: Simon@windtechglobal.com
Dr Ahmed Faheem: afaheem@windtechglobal.com
Tony Rofail: trofail@windtechglobal.com
Windtech’s Principal and Director, Tony Rofail, will present at the 7th Annual Vertical Cities conference, broaching on the topic of “Outsmarting the Wind,” where he will present cost effective strategies to enhance the aerodynamic performance of tall buildings. The presentation will draw on Tony’s depth of experience in research and industry specific expertise having headed Windtech Consultants for over 25 years.
Tony will be covering the following topics:
• The effect of different wind climates on shape optimisation strategies
• When it is feasible to modify dynamic properties to enhance aerodynamic performance for tall buildings.
• Cost effective strategies for auxiliary damping for tall buildings.
These topics are designed to aid in the accomplishment of one of the conferences goals: overcoming the challenges in developing vertically integrated supertall buildings.
The conference invites industry experts from around the world and will be taking place between the 7-9th of March in Bangkok. Tony would be happy to meet at this event to discuss ways Windtech can help overcome challenges for your current and future projects. Alternatively you may contact Tony via email via the hyperlink below.
Windtech is delighted to have contributed to both finalists from Singapore: Marina One and Oasia Downtown Hotel. These projects are nominated for the Best Tall Building in Asia & Australasia. In addition, Oasia Downtown Hotel is nominated for the Urban Habitat Award.
Windtech supported Singapore’s Marina One project (pictured above) from the early design stages providing advice with regards to the pedestrian wind environment, design wind load effect on the link bridges and the structural frame, including the effect of load transfer between the linked substructures for the residential components. Windtech also modelled the façade cladding pressures. Windtech helped provide solutions to overcome the challenges for a project with large open public spaces between the towers.
Oasia Downtown Hotel in Singapore (pictured above) was nominated for both the Best Tall Building (Asia and Australasia) as well as the Urban Habitat Award. The unique permeable façade incorporates live plants to create a living tower. Windtech were thrilled to be associated with the façade pressure studies in order to facilitate good design on such an innovative project as well as overcoming the challenge of delivering suitable wind conditions for the elevated terraces without impacting the architectural intent.
Windtech have been surpassing expectations with increased demand due to our tailored approach for each project and our robust analysis of wind effects across the globe. Let us demonstrate how we can assist in supporting good design outcomes for your next project. Email us at reception@windtechglobal.com or call us at any of our offices.
