Modeling Contaminants in Ventus

Overview

This tutorial is intended for Performance-Based Design Engineers that want to track the flow of Contaminants in their building models. It will demonstrate Contaminant tracking in a simple 2 Zone model to help you understand the basic concepts of modeling Contaminants in Ventus. You will learn how to define Species for tracking, inject Species in to your model as Contaminants, and use the Transient Simulation analysis tools in Ventus to view the Contaminant concentrations in each Zone.

Before Starting

Before beginning this tutorial:

Introduction

Contaminant tracking is an important part of many Smoke Control and Indoor Air Quality studies. Understanding how Contaminants flow from one zone to another in your models allows you to better control the dispersion of contaminants, and design systems to perform critical functions like maintaining of tenability in emergency scenarios.

In this tutorial we will create a 2 Zone model, define some Flow Paths that will control the flow between the two Zones, and inject a Contaminant in to one Zone to observe how the Contaminant transports through the model.

Creating the Geometry

The geometry for this model will be very simple and consist of only 2 Zones. To create the 2 Zone geometry:

The Zones are now ready for us to add some Flow Paths to define how air will flow between the Zones.

Defining Flow Elements

The first step to defining Flow Paths is to define the settings each Flow Path will use. This is accomplished by adding Flow Elements to the model. We will only need one new Flow Element to model an open door between the two compartments. All other Flow Paths we use will use one of the default Flow Elements available in Ventus.

To create this Flow Element:

We are now ready to use this and other Flow Elements to create some Flow Paths in the model.

Creating Flow Paths

We will create 3 Flow Paths in the model. One Flow Path will use the Door-Open Flow Element to connect the two zones, and the other two will use the default AREA/Area Flow Element to connect the two zones to the ambient boundary of the model. To create these Flow Paths.

The Flow Paths are now created and we are ready to add a Contaminant to our model.

Creating a Species to track Contaminants

To track Contaminants in Ventus, we need to first define a Species. The Species defines some fundamental data about our Contaminant, which will affect how it flows in our model. In this example, we will create a very simple Species. To create this Species:

We are now ready to inject the Species in to the model.

Defining a Source/Sink Element

To inject a Species in to the model, we will use a Souce/Sink Element. Sources/Sinks and Source/Sink Element have a similar relationship as Flow Paths and Flow Elements. A Source/Sink Element defines the parameters that are then used by an individual Source/Sink.

So to create a Source/Sink, the first step is to define a Source/Sink Element that injects our Smoke Species. To do this:

We have now created the Source/Sink Element and are ready to use it in our Source.

Creating a Contaminant Source

Now that we have the Source/Sink Element, we can use it in a Source. To do this:

We have now created a Contaminant Source in our model. We are almost ready to simulate.

Creating a pressure source

In order for contaminants to actually move through the model, there must be some source of pressure or air flow. This can range from natural effects like wind or stack effect, or forced flow effects like fans. For our model, we will add a simple fan to supply some airflow to Zone01. To do this:

We have now created the fan. All that is left before simulating is to configure our simulation settings.

Configuring Transient Settings

To model contaminants in Ventus, you must configure the Simulation Parameters to use the Transient simulation mode. To do this:

We are now configured to run the simulation.

Running the Simulation

We are now ready to run the simulations. To do this:

The simulation should complete in a matter of seconds, and you should see the 3D Flow Path visualizations update in real time, showing the flow vectors at each Flow Path.

Viewing Results

We are now ready to view the results of how our Contaminants have moved throughout our model. To view the results:

Conclusion

As you can see from the results, the Smoke is generated in Zone01 and moves through the Door-Open Flow Path to then contaminate Zone02.

Now that you are familiar with how to model Contaminants using Species, inject those Species in your model, and view Contaminant concentrations using the transient simulation and analysis tools in Ventus, you should be able to apply these same skill to your own models.

To download the most recent version of Ventus, please visit the Ventus download page. Please contact support@thunderheadeng.com with any questions or feedback regarding our products or documentation.