These Indoor Wildfires Help Engineers Study the Real Thing | National Geographic

Fire, especially wildfire, is a really complex phenomenon. I hear people talking about being able to control fire; I don't think that's something that will happen soon. But here we are, at least trying to understand fire. There are factors that affect fire from the individual leaf clear up to the top of the atmosphere.

The current model that we use to print helps us predict fire spread; it was about 40 years old. So what we're doing with these experiments is probing deeper and trying to provide more information about how fire spreads in wildlands. Today, we're going to run different types of experiments, and we're trying to understand under which conditions the fire, if it ignites on the surface, will transition and spread.

This is replicating dead fuels, which is typically on the ground. What catches easily on fire is the dead fuel. This one you see here with the leaves; this is what we call the live fuel. The live fuels are collected locally, so it's very important for us to study the specific fuel here because it's such a great contributor to the wildfires that we get in the region.

The wind tunnel is instrumented with a barrage of instruments that includes temperature probes or thermocouples, heat flux sensors, relative humidity sensors, and load cells that are measuring mass loss. If you are ready, we're right away once our computers are ready and our cameras all set. We're ready to ignite! Are we all ready?

Our study wants to focus on if the dead fuels do catch fire through lightning or a cigarette butt or something, whether that will transition to the actual live shrub. Once it gets to the live shrub, we want to know if it's going to spread throughout the whole shrub community. Today, we are varying wind speed in this experiment, applying more oxygen to the fire so it can consume fuels much faster.

In experiments where we have fire, it is much more intense; flame height is much higher. Wind will help those flames to be tilted, which will enable neighboring fuel to ignite faster. Eight hundred to fifteen hundred Fahrenheit. We worked with the Forest Service to provide them information that they need to manage the land.

Wind blowing this way, you've got flames that are able to go past this. Here in California, we have a condition called Santa Ana winds, which are high-speed winds that could cause destructive fires. Wind is probably one of the most important factors that affect fire spread.

We're modeling it to control as much as we can so we can really understand what the important variables are. Down the road, we hope to have a perfect computer model that we simply ask: if ignition occurs in this part of a forest under certain conditions, what will happen within the next 30 minutes? Within one hour, what would be the best way to deploy resources?

Global climate change is going to bring more wildfires with greater intensity in areas like Southern California. In order to combat them, we need to understand them, know how to predict them, and know how to fight them.