Windtech was commissioned by Health Infrastructure NSW and Multiplex to undertake a holistic assessment to ensure the operational integrity of the helipad infrastructure for the John Hunter Health and Innovation Precinct (JHHIP), Newcastle. To meet this operational need, Windtech conducted the following studies:

Through “Desktop” analysis, we were able to assess the likely impact of the redevelopment of the John Hunter Health and Innovation Precinct (JHHIP), located in Newcastle, on the local wind environment at the critical outdoor areas within and around the subject site, the wind entry effects, and the effect of the helicopter travelling to and from the helipads.

Furthermore, our team conducted detailed evaluations of wind speed and turbulence specific to the Acute Services Building Helipad, identifying potential hazards and implementing tailored strategies to mitigate risks and ensure safer and effective aircraft operations.

Implementing CFD modelling methodologies, Windtech conducted an Air Quality/Pollution Dispersion Study, to analyse the dispersion patterns of helicopter exhaust plumes onto the ASB Building air intakes. This comprehensive assessment assessed the effect of the proposed design on the spread of NOX compounds on and around the site. The cumulative directionally weighted average of the NOX results showed no exceedance at the HVAC intakes of the proposed development. Moderately strong odours were predicted in certain areas and various mitigation treatments were recommended.

Image 1.1 Cumulative NOX Contours weighted by frequency of occurrence of each wind direction, Plan View

Figure 1: Cumulative NOX Contours weighted by frequency of occurrence of each wind direction, Plan View

Cumulative NOX Contours weighted by frequency of occurrence of each wind direction, Eastern Aspect

Figure 2: Cumulative NOX Contours weighted by frequency of occurrence of each wind direction, Eastern Aspect

Image 1 CO Air Quality Category

Figure 3: CO Air Quality Category contours. Cumulative CO Contours weighted by frequency of occurrence of each wind direction. Contours are plotted 1.5m from ground (Left) and 1.5m from floor level of the terraces (Right)

Windtech Consultants are committed to providing accurate and reliable modelling to guide the design of helipads to enable safe and functional operation.

If you are working on any projects that could benefit from the capabilities presented in this article, please reach out to our regional offices Sydney & Melbourne, Australia, London, UK, Mumbai, India. New York & Miami, USA, Dubai, Hong Kong, Singapore, and Toronto, Canada we guarantee to support you wherever you are based.

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In the realm of architecture and urban planning, the challenges posed by wind-driven rain (WDR) are often underestimated, leading to significant form and aesthetic consequences for buildings. This article delves into the critical role of Windtech’s Computational Fluid Dynamics (CFD) Wind Driven Rain studies in addressing these challenges, offering innovative solutions that revolutionize building design and occupant comfort.

The Overlooked Challenge of Wind-Driven Rain

The issues arising from neglecting WDR in architectural design are profound. Inadequate consideration of WDR can result in water infiltration, causing damage to building materials, building contents as well as infrastructure such as lifts and escalators. This results in reduced lifespan of structures, and increased maintenance costs. Moreover, it can significantly impact the comfort and well-being of occupants, especially in outdoor communal spaces as well as the viability of retail tenancies.

The Power of CFD in WDR Analysis

Windtech utilises advanced Computational Fluid Dynamics modelling to accurately simulate the complex interactions between wind, rain, and architectural structures. This technology allows for precise modeling of rain patterns and their impact on buildings under varied wind conditions. By employing CFD, architects and planners can pre-emptively identify potential problem areas in building designs.

Assessing Wind-Driven Rain Effects

Windtech’s CFD studies include accounting for wind speed, wind direction, rain intensity, and the specific architectural features of a building. These elements are crucial in creating accurate models that predict how rain will interact with a structure, thereby enabling more informed design decisions. The key assessment points are as follows:

1. Areas of Concern: Areas on concern are identified and confirmed with the key stakeholders, these may include entrances, terraces, balconies and covered public spaces.

2. Climate analysis: A detailed statistical wind driven rain model is developed for the regions. This includes analysing the relationship between wind speed, wind direction, measured rainfall and rainfall intensity. This model is then refined to match wind conditions at the development site.

3. Simulation of WDR: The wind driven rain is simulated at the site. These simulations model the interaction between then wind and the rain. In these simulations a range of rain droplet sizes are included. The wind may significantly alter the raindrop trajectories, enabling rain to bypass traditional barriers such as overhangs and awnings. Wind can drive rain horizontally (or even upwards, depending on the wind’s velocity and direction) into seemingly protected areas like covered terraces and balconies.

4. Visualizing Wetted Surface Area: The report presents cumulative Wetted Surface Area contours to visualize surface wetting and rain accumulation under canopies and awnings at ground level under different wind conditions. These figures are easy to interpret and summaries the results of multiple simulations.

5. Mitigations Measures: If required mitigation measures can be designed and tested using these results

Case Study: One Holland Village, Singapore

The Windtech CFD Wind Driven Rain Study for the One Holland Village project in Singapore provides a detailed analysis of the effects of wind-driven rain on the development. The study utilized Computational Fluid Dynamics (CFD) to model and analyze the impact of rain in combination with various wind directions on the structure. Key findings from the study include:

1. Lower Levels Analysis (Levels 1 to 4): The study found that wind-driven rain would be concentrated in sections lacking local shading or overhangs. Areas fully exposed were likely to see moderate rain accumulation, with variations across different wind directions.

2. Elevated Terraces Analysis (Levels 20 and 33): Rain accumulation levels at elevated terraces were strongly correlated with wind direction. The study provided detailed insights into how different areas of these terraces would be affected by rain under various wind conditions.

To address these issues, the study recommended design modifications. These included the implementation of architectural features such as overhangs, screens, or shelters in areas where rain accumulation was predicted to be high. By incorporating these elements, the design aimed to reduce rain penetration into vulnerable areas, thus enhancing the overall functionality and comfort of the building’s spaces. This approach exemplifies how targeted design interventions, informed by
detailed CFD analysis, can effectively mitigate wind-driven rain impacts in urban structures.

Windtech’s Unique Approach

In the field of wind-driven rain (WDR) assessment, Windtech sets itself apart with a distinctive performance-based approach. This method is a testament to our commitment to leveraging cutting-edge technology and research in the CFD industry. At Windtech, we utilize the latest published methods and incorporate our own proprietary techniques and tools, ensuring our analysis aligns with current world best practices.

The cornerstone of our methodology is the integration of comprehensive environmental data, advanced CFD modeling, and our proprietary algorithms. This combination enables us to accurately simulate real-world scenarios, providing detailed insights into potential WDR impacts. Our approach goes beyond mere prediction; it offers actionable recommendations for design modifications that can effectively mitigate WDR effects.

Concluding Thoughts

Incorporating Windtech’s CFD Wind Driven Rain Study into the design process brings numerous benefits. It leads to structures that are not only visually appealing but also functionally robust against the challenges of wind-driven rain. This approach ensures the longevity of buildings, enhances the comfort of occupants, and promotes sustainable architectural practices.

In conclusion, the Windtech CFD Wind Driven Rain Study is an indispensable tool in modern architecture, offering innovative solutions to the challenges faced in urban environments, particularly in regions prone to intense and frequent rainfall. By embracing such advanced methodologies, Windtech positions itself at the forefront of wind engineering, setting a new standard in the design and sustainability of urban structures. This innovative approach not only addresses the immediate concerns related to WDR but also paves the way for future advancements in architectural resilience and sustainability.

Fish Market Rendering

Windtech has had the privilege to work collaboratively with prominent local architectural firm BVN in association with Danish architectural firm 3XN, on the iconic flagship project that is the New Sydney Fish Market. Windtech also worked closely with the project’s principal contractor, Multiplex through detailed design process.  The NSW Government is delivering a new Sydney Fish Market which will retain its authentic experience and strengthen its position as one of Australia’s leading tourist destinations.

Windtech was appointed to conduct extensive wind engineering services on the $750 million project from mid 2017 to mid 2023. This monumental development, located in the Blackwattle Bay precinct, will deliver over 6,000 square meters of new public open space within a 4-storey market hall along with restaurants, cafés, bars, fishmongers, specialty food retailers and other world-class amenities and attractions, which will be joining Sydney’s renowned harbourside. The New Sydney Fish Market not only represents a significant step forward in the realm of modern seafood commerce but also incorporates the latest technological advances. Throughout its construction, this monumental development has generated more than 700 jobs, and upon becoming fully operational, it is estimated to sustain an additional 700+ jobs, contributing to both economic growth and the infusion of advanced technology into the industry.

New Sydney Fish Market Internal and External Rendering

Figure 1: Aerial and Internal perspectives of the New Sydney Fish Market

The most noticeable feature of this building is undoubtedly the distinctive wave-shaped and scale-patterned roof. During the Design Development phase, Windtech was commissioned to conduct a Long Span Roof Structural Loads Study to accurately determine the wind loads on both the cladding and the loads on the structure. This required careful consideration of the effect of the scales on the overall wind drag. Testing was performed at one of the 3 boundary layer wind tunnel facilities, located at Windtech’s global head office in Sydney, using a detailed 3D printed 1:300 scale model of the development. From conducting this study it was possible to provide detailed and accurate design pressures for each facet of the building envelope as well as load cases in the form of net panel pressures (including 42 panels for the roof), which is not possible using wind loading standards for such an unusual building forms.

Maximum and Minimum Roof Pressure

Figure 2: Contours of Maximum (LHS) and Minimum (RHS) net roof pressures.

A detailed wind environment study was undertaken for the various outdoor areas as well as an assessment of the Universal Thermal Comfort Index (UTCI) for some critical outdoor spaces, which provides a more wholistic assessment of the outdoor comfort, accounting for local wind speeds, temperature, humidity, and solar radiation.

A study was also undertaken to assess the impact of wind loads on two types of door closers by applying incremental wind loads to the proposed pivot door system, within our wind tunnel. Windtech also carried out a Solar Reflectivity Study to assess the potential glare impact from the structure including reflections from the faceted roof.

Fish Market Wind Tunnel Model.

Figure 3: Windtech’s wind tunnel study model

 

Motion Dampers for Tall Building

Introduction:

In today’s dynamic urban landscape, the demand for tall buildings is on the rise, driven by factors such as population growth and the need for sustainable urban development. As cities across the world reach for the sky, engineers and architects are faced with the challenge of not only designing structures that meet stringent safety standards but also ensuring that occupants experience a comfortable environment.

One crucial aspect that comes into play in the design of tall buildings is the consideration of wind-induced motion. In recent times, fire hydrant tanks have emerged as an important part of performance-based fire design, particularly for buildings exceeding 135 meters in height – according to the Australian building Code (NCC 2022) buildings above this height are not amenable to the deemed to satisfy provisions in AS 2118 due to higher system pressure requirements. 

Potential Dual Role of Fire Hydrant Tanks:

Beyond their primary function in fire safety, fire hydrant tanks have revealed an unexpected yet highly valuable secondary role in enhancing building comfort. Tall structures, while marvels of modern engineering, can be susceptible to wind-induced motion. Just as individuals have varying thresholds for experiencing motion sickness on a ferry, the sensitivity to building motion varies widely. While established criteria exist for acceptable building acceleration levels, it’s important to acknowledge that there will always be occupants who may feel uncomfortable, even within these prescribed limits. Adapting the same fire hydrant tanks to also serve as tuned liquid motion dampers (TLDs) is a very cost-effective way of accommodating these more sensitive occupants even where the building accelerations happen to meet the prescribed criteria. 

Tuned Liquid Dampers: A Cost-Effective Innovation:

Conventional methods of stiffening a building, while effective in some cases, can be costly and may inadvertently exacerbate sensitivity to motion. Increasing structural rigidity can bring the natural frequency closer to the peak of the human body’s response spectrum, potentially heightening sensitivity to motion. This is where TLDs emerge as a cost-effective solution.

Unlike traditional approaches, tuned liquid dampers operate by reducing building motion without the need for increased structural stiffness. This innovative technique not only proves highly effective but is also remarkably cost-effective, especially when integrated with an existing fire hydrant tank.

Customization and Optimization:

The engineers at Windtech Consultants have honed the art of tailoring fire hydrant tanks to harmonize seamlessly with a building’s natural frequency. This optimization enhances their efficiency as tuned liquid dampers. Moreover, Windtech has developed ingenious energy dissipation techniques within these tanks, incurring minimal additional costs.

Practical Considerations: Reinforced Concrete Tanks:

From a logistical perspective, clients often lean towards reinforced concrete tanks. This choice not only sidesteps extended lead times but also avoids the associated expenses of alternative fabrication methods. Windtech’s expertise in streamlining damper designs during peer reviews has yielded substantial cost savings.

The engineers at Windtech have been able to develop the most cost-effective forms of energy dissipation devices within these tanks at negligible cost. From a logistic standpoint our clients tend to opt for a reinforced concrete tank to avoid the long lead times and costs associated with other fabrication methods such as metal plates or GRC panels. 

Real-World Savings: Case Studies:

Whenever we are asked to peer review a damper design, we tend to be able to simplify the design to achieve significant cost saving. This especially happens when we are dealing with a regular tall building where a Tuned Mass Damper or some proprietary system is proposed – in these cases many millions of dollars can be saved. Even for a a recent case where a TLD damper was already proposed, we were able to significantly simplify the design of the TLD damper to achieve a staggering USD$300,000 in savings. In another instance, the additional cost of converting a fire hydrant tank into a tuned liquid damper amounted to as little as USD$50,000. At that price, it would make sense to include such a measure even if the building acceleration is just inside the target criterion, given the broad range of sensitivity of humans to building motion.

Motion Dampers for Tall Building

Figure 1. Measuring Dynamic Properties of The42, Kolkata, Dattatreya Das (Left), Aaron Lefcovitch (Right)

Conclusion: Pioneering a New Era in Building Design

As cities continue their upward trajectory, the integration of fire hydrant tanks as tuned liquid dampers represents a significant advancement in tall building design. By addressing both fire safety and building comfort in a synergistic manner, engineers and architects are ushering in a new era of innovative and cost-effective solutions.

In this rapidly evolving field, Windtech Consultants stands at the forefront, offering tailored expertise to ensure that tall structures not only reach for the sky but also provide a safe and comfortable environment for their occupants.

If you are working on any projects that could benefit from the capabilities presented in this article, please reach out to our regional offices Sydney & Melbourne, Australia, London, UK, and Mumbai, India. New York & Miami, USA, Toronto, Canada, DubaiHong Kong & Singapore, we guarantee to support you wherever you are based.

To get regular updates on news and events, please follow us on our LinkedIn page.

Rendering of the proposed development, looking northeast from Paperbirch Drive (Diamond Schmitt Architects)

150 The Donway West and 4 Overland Drive, located in the Don Mills area of North York, is a perfect example of the intensification necessary to meet the increased housing demand resulting from high population inflow to the Greater Toronto Area (GTA) and the unaffordability of homeownership in Ontario. Akelius plans to build up the existing two-building site by adding two new residential market-rate rental buildings, as shown in Figure 1 below.

Rendering of the proposed development, looking northeast from Paperbirch Drive (Diamond Schmitt Architects)

Figure 1. Rendering of the proposed development, looking northeast from Paperbirch Drive (Diamond Schmitt Architects)

Diamond and Schmitt designed the two new mid-rise buildings to complement the existing structures by incorporating a brick similar to that used in the existing rental buildings. They then enhanced the façade with glass and white metallic features while maintaining the boxy shape to integrate old and new aesthetics fully. The project also involves the addition of two underground parking levels and a central courtyard, so not only would this project target the undersupplied rental market while providing transit accessibility, but it would also improve the ground level and below-grade conditions of the existing site with soft and hard landscaping.

Windtech was pleased to provide the pedestrian wind environment study for the site as a part of the requirements set forth by the City of Toronto for site plan approval. Ellen Marejka, an Associate Director of Windtech’s Toronto Office remarks, “As you can imagine, wind contributes to human comfort and can impact everyday activities whether it be waiting at a bus stop or sitting on a park bench. The wind comfort, and even thermal comfort, of outdoor public spaces, is crucial to the functionality of the overall design. A pedestrian-level wind study strives to address any of these wind concerns at the site before any groundbreaking or actual construction occurs. This is done by ensuring the wind conditions on and around the site are within acceptable comfort criteria throughout all seasons”.

But what triggers the need for a pedestrian wind study?

Toronto classifies the need based on the location of the development and the height of the building. Generally speaking, the taller the building, the greater the need. The City accepts two types of wind studies: wind tunnel studies (which was the approach in this project) or computational fluid dynamics modelling (which Windtech also offers).

With the help of the architect and developer, Windtech created a digital model of the study buildings and the “proximity model” or “surrounds” (both terms are used to describe the surrounding environment, shown in grey in the figure below).

Blade Walls of the Surat Diamond Bourse Building

Figure 2: The digital 3D surround model of the site looking north, with the proposed development shown in blue.

Once the digital model was created, a physical model was fabricated out of foam using computer-aided manufacturing. Pressure sensors were installed at the ground-level locations, and each location was classified based on Table 1 below. The model was placed on a turntable in one of our four wind tunnels and tested at the prescribed number of wind directions. There were two testing scenarios completed: the existing site conditions without the proposed development and the site conditions with the proposed development.

The 3D surround model of the site in the wind tunnel looking north, with the proposed development constructed with blue foam.

Figure 3: The 3D surround model of the site in the wind tunnel looking north, with the proposed development constructed with blue foam.

The results of the wind tunnel study were compared to the comfort criteria in Table 1. For the most part, the results were within acceptable limits. However, where the comfort criteria were exceeded, and a location was deemed too windy, Windtech proposed mitigation measures to alleviate the wind effects. This includes a 3m awning to span the south and western corners of the 150 The Donway West building and densely foliating evergreen landscaping features in the courtyard region. These mitigation features would reduce the wind to an acceptable level while having the least possible impact on the architectural design or aesthetic features.

Table 1: Wind Criteria for Pedestrian Comfort and Safety (City of Toronto, 2022)

Wind Criteria for Pedestrian Comfort and Safety (City of Toronto, 2022)

There is a growing need for more purpose-built rental developments in the GTA like the one proposed by Akelius. As mentioned by Shaun Hildebrand from Urbanation: “The GTA rental market remained substantially undersupplied during the first quarter of 2023. Even though supply is set to increase in the near-term, it is expected to be short-lived and insufficient to offset demand.” While this two-building development proposes the addition of much needed 242 rental units, there are bigger plans to develop and intensify the Don Mills area to meet population demands. Currently, there are ten development applications within a 1-kilometre radius as shown in Figure 4.

Development applications in the Don Mills area surrounding the proposed site (from submission to the City of Toronto)

Figure 4: Development applications in the Don Mills area surrounding the proposed site (from submission to the City of Toronto).

Windtech is happy to announce that we have opened an office in Toronto to serve our clients in the GTA better. We offer wind environment studies wind tunnel studies (like this one), or CFD studies for new developments in accordance with the city requirements. This type of wind study is required for site plan approval in most urban municipalities in southwestern Ontario.

If you are working on any projects that could benefit from the capabilities presented in this article, please reach out to our regional offices Sydney & Melbourne, Australia, London, UK, and Mumbai, India. New York & Miami, USA, Toronto, Canada, Dubai, Hong Kong & Singapore, we guarantee to support you wherever you are based.

To get regular updates on news and events, please follow us on our LinkedIn page.