0
Share 
Creating walkable, livable cities requires understanding how people experience the outdoor environment. Pedestrian outdoor comfort analysis is crucial for urban planning and design. This field studies the key factors that impact pedestrians’ perceptions of public spaces, including temperature, humidity, sunlight, wind, noise, and air quality.
One major challenge is predicting localized wind speeds and patterns around buildings and open areas. Strong gusts can create discomfort and even pose safety issues for pedestrians. However, traditional wind tunnel testing has limitations in capturing small-scale turbulence.
To solve this challenge, we can use a tool called CFD, which can simulate how the wind flows and changes around complex shapes and landscapes.
According to a study by CCTech, CFD can reduce the simulation time and cost by up to 90% compared to wind tunnel testing.
In addition to capturing the effects of boundary factors such as vegetation, building dеsign and oriеntation, height and spacing, CFD can offer high-resolution information on wind spееd and dirеction and prеssurе and an’ tеmpеraturе.
The goal of this blog post is to еxplain what CFD is and how it can help us study how people feel in the outdoor environment.
CFD is a tool that can simulate the wind flow and turbulence around buildings and open spaces using numerical methods and algorithms. It can help evaluate and optimize the pedestrian comfort and safety in different scenarios, such as:
Early stage design: CFD can provide a quick and low-cost way of assessing the viability of a project and its impact on the outdoor environment before committing to more detailed and expensive wind tunnel testing. It helps identify potential wind comfort and safety issues early in the design process and suggest possible solutions or improvements.
Outdoor space utilization: CFD created a connection between the indoors and outdoors and encourages vibrant outdoor places and spaces for the ‘Walkie Talkie’ building in London. It can advise where to locate outdoor amenities, such as terraces, pools, restaurants, or event areas, and how to design them to maximize their use and enjoyment.
Wind mitigation strategies: CFD develops and tests different wind mitigation strategies, such as adding or modifying building elements, landscaping features, or wind barriers, to reduce or eliminate the negative effects of wind on pedestrians. It also optimizes the wind mitigation strategies to achieve the desired level of comfort and safety without compromising the design quality or integrity.
Indeed, while CFD is a robust tool for analyzing pedestrian comfort, it does come with its own set of challenges:
Data Availability and Accuracy: The accuracy of CFD simulations heavily depends on the quality and availability of input data. Inaccurate or incomplete data can lead to misleading results.
Model Complexity and Computational Cost: CFD models can be complex and computationally expensive. They require significant computational resources, which can be a limiting factor, especially for large-scale urban simulations.
Validation and Verification: Validating and verifying CFD results can be challenging. It’s crucial to cross-compare CFD simulations with wind tunnel experiments and field measurements.
Interpretation and Communication of Results: Interpreting CFD results requires a deep understanding of fluid dynamics. Moreover, effectively communicating these results to non-experts can be challenging.
To overcome these challenges, here are some best practices and recommendations:
Use High-Quality Data: Ensure the data used for simulations is accurate and complete. This includes wind speed, direction, temperature, and other relevant parameters.
Optimize Model Complexity: Balance between model complexity and computational cost. Use appropriate turbulence models and discretization schemes.
Cross-Comparison for Validation: Validate CFD results by cross-comparing with wind tunnel experiments and field measurements. This can help in identifying and correcting any discrepancies.
Clear Communication of Results: Use visual aids and simple language to communicate CFD results. This can help non-experts understand the implications of the results.
Follow Best Practice Guidelines (BPGs): BPGs have been developed for conducting CFD analysis of the wind environment in urban areas. These guidelines are based on the cross-comparison between CFD simulations, wind tunnel experiments, and field measurements.
Mechartes is an engineering and IT services company specializing in CFD (computational fluid dynamics), FEA (finite element analysis), and acoustic analysis. We have a team of highly qualified engineers with domain expertise in mechanical and software engineering.
We can help you to:
Improve walkability using pedestrian outdoor comfort analysis with CFD.
Derive accurate simulation results with a professional approach and an engineering mindset.
Assess your project’s viability and its impact on the outdoor environment. This is executed before committing to more detailed and expensive wind tunnel testing.
Explore and compare different design options and alternatives and evaluate their performance and impact on the wind conditions around the site.
The case study demonstrated the effectiveness of CFD for pedestrian level wind comfort analysis, highlighting its benefits in saving time, reducing costs, and enhancing the design process.
The aim was to show how CFD can save time and money and make the design process easier in certain circumstances.
Engineers used two primary tools for modeling winds around buildings: a CFD simulation tool and wind tunnel testing (WTT). The choice of tool depends on the type of building project, such as the building’s complexity, height, location, local or municipal requirements, and local climatic conditions.
The article outlined five scenarios where a CFD approach may be beneficial:
Early in the design process: CFD is a relatively low-cost and quick way of assessing the viability of a project early in the design phase.
Maximizing the use of outdoor space around the building: CFD wind comfort studies can inform where to locate these spaces throughout your project site and develop wind control strategies to maximize the use of these amenities.
Exploring and comparing design options.
The outcome of using CFD for pedestrian level wind comfort analysis was positive. It helped identify and solve complex challenges of a design sooner, saving time and avoiding costly mistakes later. It also provided the necessary data to support how a building’s design will create positive outdoor experiences.
To know more about this in detail, click here.
CFD is crucial in pedestrian outdoor comfort analysis, providing valuable insights into wind conditions around urban spaces. Despite data accuracy, model complexity, and result interpretation challenges, it is a cost-effective and efficient tool for early design stages, outdoor space utilization, and wind mitigation strategies. By adhering to best practices, we can harness the full potential of CFD to improve walkability and create comfortable outdoor environments.
For more insights and expert guidance on pedestrian outdoor comfort analysis using CFD, feel free to reach out to Mechartes, a leading provider of CFD, FEA, Piping, Vibration, and Acoustic Analysis solutions.
Contact us now!
0
Share 
facebook