Tutorial: Pedestrian Wind Comfort Analysis

Overview

SimScale has introduced Pedestrian Wind Comfort simulation into its platform that can be used to assess the external aerodynamic effects of a building in respect to its environment.

This tutorial provides a step-by-step guide on how to set up a pedestrian wind comfort analysis simulation.

Result of Pedestrian Wind Comfort Simulation done with simscale — Result of Pedestrian Wind Comfort Simulation

Create Simulation

As a first step, import the tutorial project into the SimScale workbench.

Import tutorial project into workbench

By importing the tutorial project, a new project will be created for you, and the ‘Workbench’ will open with the prepared tutorial geometry already loaded into the viewer.

View of SimScale workbench at beginning — View of Workbench

To create a new simulation, click on the “+” button next to ‘Simulations’ in the tree or the “Create Simulation” button on the geometry panel.

First step in how to start creating a simulation in SimScale — How to Start Creating a Simulation

Select the “Pedestrian Wind Comfort” analysis type and click “Create Simulation“.

Simulation Dialog Box — Choosing a Simulation

A new simulation tree will be shown

Simulation Tree of SimScale — Simulation Tree

All setup steps that are completed are highlighted with a green check. Steps that require some user input are shown with a red circle. Steps that have a blue circle indicate optional settings.
For this tutorial, a pedestrian wind comfort analysis is automatically chosen

Simulation Setup

Geometry

The geometry is automatically assigned to this simulation.

Region of Interest

The region of interest is the area where the simulation will be restricted to.

Here is a brief explanation of the settings that are available:

Disc Radius : The radius of the area that we want to cover
Center point : The center point of the area that we want to simulate
Ground height: The ground height for the wind tunnel for the simulation
North angle: The north angle that will be used in the simulation

The settings for the region of interest can be configured based on the the need for the simulation.

Wind Conditions

The wind conditions that will be used in the simulation can be set automatically by entering a location for the simulation.

After entering a location, it will show the chosen location and the details of the data that is used. The wind engineering standard that is used and the coordinates of the location is shown.
There is also an option to manually import wind data if available.

Wind Data dialog box for pedestrian wind comfort in SimScale — Wind Data Dialog Box

Wind Rose Generated Based on Selected Wind Data for pedestrian wind comfort tutorial in SimScale — Wind Rose Generated Based on Selected Wind Data

After selecting the wind data that will be used for the simulation a wind rose will be generated and it will show the different wind speeds coming from different directions. The number of wind directions can be changed depending on the need of the simulation.

Defining Terrains of Different Direction for pedestrian wind comfort tutorial in simscale — Defining Terrains of Different Direction

Wind exposures of the different directions can also be modified depending on the terrain.

The blue check button in the top right can be clicked to confirm the wind data that was selected before and will be used in the simulation

Pedestrian Comfort Map

Pedestrian comfort map is used to define at which height the simulation will run. However, the default value will be enough for this simulation

Defining Ground Level for Simulation for pedestrian wind comfort tutorial in SimScale — Defining Ground Level for Simulation

Height above ground: The height where the simulation will run at
Ground: Defines the definition of the ground of the geometry. There is two options:
- Ground relative: This option uses assigned faces as reference
- Absolute: This option uses the bottom of the region of interest as reference

Simulation Control

In Simulation Control, the default values will be enough for the simulation.

Advanced Modelling

Under advanced modelling, surface roughness of selected volumes can be defined and define porous objects in the domain. However for this simulation, it is not necessary to do so.

Defining Surface Roughness and Porous Objects for pedestrian wind comfort tutorial in SimScale — Defining Surface Roughness and Porous Objects

Mesh Settings

Under mesh settings, the fineness of the mesh can be selected. The selection is ranged from very coarse to very fine. A coarse mesh will be sufficient for this simulation.

A target size can also be selected to define the minimum size for a cell size. Refinements can also be made if necessary

Start Simulation

Now the simulation setup is complete and you’re ready to start your simulation. To begin the simulation, a simulation Run needs to be created. A simulation Run creates a snapshot of the current setup and tries to compute the results based on the snapshot settings.

To create a new Run, click “+” next to Simulation Runs. Name your simulation and click on “Start“.

Create a New Simulation Run for pedestrian wind comfort tutorial in SimScale — Create a New Simulation Run

Results

Computation of the results can take up to a few hours. You’ll be informed via email once your simulation run is finished. Once finished, you’re ready to analyze the results.

When the simulation is finished, click on “Statistical surface solution” down in the simulation run tree (or click “Post-process results” in the run panel) to post-process the simulation results. The integrated online post-processor will open.

How to view simulation results in SimScale — Viewing Results

Select “Statistical surface solution” and the result of the simulation will be displayed. There is also an option to change different wind comfort criterion in the dialog box in top right.

Wind Comfort Analysis Based on Lawson Criterion in SimScale — Wind Comfort Analysis Based on Lawson Criterion

Congratulations! This concludes this pedestrian wind comfort analysis tutorial.

Last updated: March 27th, 2020

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