The document discusses the influence of building aerodynamics on pedestrian wind comfort, showcasing SimScale's cloud-based simulation platform designed for analyzing these effects. It outlines a workflow for simulating pedestrian wind comfort, identifying uncomfortable zones caused by building configurations, and suggests mitigation strategies. The document highlights specific examples and outcomes related to wind effects, such as downwashing and channeling, and emphasizes the importance of understanding these dynamics for urban design.

1. By Arnaud Girin
CFD webinar
Basics of Building Aerodynamics and
Their Effects on Pedestrian Comfort

2. About SimScale
Who we are
● Founded in 2012
● Offices in Munich, Boston, and New York
● 80+ employees across 6+ time zones
● 150,000 users worldwide
● More than 300k simulation projects

3. We created the world’s first cloud-based
engineering simulation platform.
● Fluid dynamics (CFD)
● Solid mechanics (FEA)
● Thermodynamics
All accessible via a web browser.
About SimScale
What we do

4. In today’s topic, we will explore the wind
effects produced by building designs and
urban layouts on the wind comfort of
pedestrians using results from SimScale's
highly automated Pedestrian Wind Comfort
analysis type.
Today’s application
Building
Aerodynamics

5. Setup and run a
simulation
Lawson Criteria
Assess directional
results
1
3 part workflow
1. Run a PWC simulation on SimScale
2. Look at the wind comfort criteria and identify the
areas of pedestrian discomfort
3. Look at the wind speed results in the predominant
directions to understand how the surrounding
buildings contribute to the local discomfort.
How do we assess Impacts of buildings on
Pedestrian Comfort?
2
3

6. Overview
Reports [2] show the different outcomes in regards to
pedestrian wind comfort :
● Shops untenanted
● Parks under utilized
● Personal injury
● Venturi effect in passages
● Wind-blocking
What is wind comfort?
Today’s application
Example for mechanical wind comfort criteria [1]
[1] Adamek, Kimberley., Vasan, Neetha., Elshaer, Ahmed., English, Elizabeth., & Bitsuamlak, Girma., Pedestrian Level Wind Assessment through City Development: A Study of the Financial District in Toronto.
[2] http://www.urbanphysics.net/windcomfort.htm

7. ● Lawson
● Davenport
● NEN 8100
International wind standards
Wind criteria
To learn more,
head over to our blog!

8. Assessing the level of comfort
with multiple wind directions
Building Aerodynamics
and Their Effects on Pedestrian Comfort
Let’s look at an example!

9. ● Assessing the level of pedestrian comfort in a specific
urban area
○ Using year-round meteorological data
○ With multiple directions of wind
● Identify areas that are uncomfortable for the
designated activity
● Investigate the causes of uncomfortable zones, taking
into account wind effects generated by the
surrounding buildings
● Discuss ways of mitigating undesirable wind effects
What is the goal of this
simulation?
Pedestrian wind comfort simulation

10. Today’s example
1. The model used represent the district of
“La Defense” in Paris
2. It represents the main buildings
including the iconic “Arche de la
Defense”
CAD upload

11. Define region of
Interest
Define wind rose
Define pedestrian
zones
1
3
2 minute setup
It’s that simple.
1. Define region of interest
2. Define wind rose
3. Define pedestrian zones
How simple can it be?
2

12. Results
● Uncomfortable zones at the narrow passages
between tall buildings
Especially where these passages are
aligned with the predominant wind
directions: South, South South West ,
South West
Wind comfort criteria

13. Results
● Uncomfortable zones in other locations
Let’s investigate why this is happening!
Wind comfort criteria

14. ● All these wind directions are computed for 3
passes, so that regular wind patterns are fully
developed/formeds
● The results are shown for the pedestrian region
defined previously
16 directions, at once!
Results

15. What are the wind effects
affecting pedestrian comfort?
Let’s find out!
Building Aerodynamics
and Their Effects on Pedestrian Comfort

16. What are the different wind effects
generated by buildings?
Today’s application
Downwashing [1] Channeling [1] Corner Acceleration [1]
[1] Georgian Court Redevelopment Report, Burlington, ON, Rowan Williams Davies & Irwinn Inc. (RWDI)

17. Corner acceleration
Velocity contour at 1.5 m height
What are the different wind effects generated by buildings?
From south west

18. Channeling effect
What are the different wind effects generated by buildings?
(Source: https://i.stack.imgur.com/gTqm4.png )
Velocity must increase as it passes
through a constriction.
Buildings and other obstructions
will force an increase in wind speed
through city streets and other
unobstructed channels.
From south west

19. Downwash effect
What are the different wind effects generated by buildings?
Wind velocities at 6.5 m/s at low altitude
From south west

20. What can we do to mitigate these effects?
Building Aerodynamics
and Their Effects on Pedestrian Comfort

21. For entrances, where pedestrian can linger:
● Install canopies to counter the downwash effect
● Use entrance recessing
● Position entrances away from corners
What can be done?
Reducing the impact of wind effects
Photo credit : Rowan Williams Davies & Irwin Inc.

22. For specific exposed area,
● Use trees or create green spaces
● Install urban furniture such as panels, fences,
trellises
For a whole exposed layout,
● Promote main streets angled with prevailing
winds
What can be done?
Reducing the impact of wind effects
Wind diversion by using plants[1]
[1] http://www.cleanenergybrands.com/
[2] Photo credit : Rowan Williams Davies & Irwin Inc..
Main street angled vs aligned with
prevailing wind [2]

23. Want to Learn more?
Check out the articles below.
Additional Resources
● Pedestrian-level wind conditions around buildings: Review of
wind-tunnel and CFD techniques and their accuracy for wind
comfort assessment
● CFD simulation for pedestrian wind comfort and wind safety in
urban areas: General decision framework and case study for
the Eindhoven University campus
● Pedestrian Wind Environment around Buildings: Literature
Review and Practical Examples