Researchers at CU Boulder are using computations and experiments in a new sloping wind tunnel to study how wildfires form and move across different landscapes; applying cutting edge research tools to understand an old problem that Colorado has become quite familiar with in recent years.
Associate Professor Peter Hamlington leads the project. His group develops computational tools which allow researchers to understand how fire reacts at a variety of scales. Associate Professor Greg Rieker's team, including PhD student Amanda Makowiecki, developed and built the “WindCline” – a wind tunnel that can tilt up and down. They did so in consultation with Aerospace Engineering Assistant Professor John Farnsworth. The tunnel allows researchers to study how various fuels react to different conditions and allows for the study of emissions in a controlled setting using laser sensors.
Rieker and Hamlington said wind tunnels are traditionally used in studies of airplanes and car aerodynamics, but this sloping wind tunnel designed for wildfire research is the only of its kind anywhere in the world. It enables the CU College of Engineering and Applied Science team to reliably reproduce natural wildfire conditions in a way that has not previously been possible.
“Wildfires contribute to property damage and environmental impacts from emissions to possible groundwater contamination,” said Hamlington, who is part of the Department of Mechanical Engineering. “The tools we are bringing to bear on this problem are new for any type of combustion research, so we are taking the latest and greatest from one field and applying it to another. We are unique in the field of combustion research, so we are unique in the field of wildfire research.”
Wildfires are increasingly a problem in western states. In 2018 alone, Colorado saw 1,328 fires accounting for 475,800 acres burned according to the Insurance Information Institute. Researchers are being asked to help understand these events from many perspectives.
The WindCline was originally constructed through a research award from the Department of Defense’s Strategic Environmental Research and Development Program to examine the environmental impacts of prescribed burns on DoD property. Hamlington said the $1.1 million project uses adaptive mesh simulations and frequency comb laser diagnostics to give detailed info about many aspects of the fire.
“Ultimately, the proposed research will bring together two cutting-edge technologies, simulations using adaptive mesh refinement and frequency-comb laser diagnostics, for the first time in wildland fire research,” he said.
The ability to tilt and manipulate the flame in a lab environment could also help with a variety of research questions relating to how topography affects the fires. Studying how the flames react going uphill is especially important. That’s because fire usually travels uphill much faster than down. On the incline, before the fire even arrives, soon-to-be scorched areas have already been warmed by heat waves off the fire.
Rieker, who is also in the Mechanical Engineering Department, said this is quickly becoming an important research area for the college.
“It is an important research area for our region as well,” he said. “We are now planning a new project in the WindCline involving five CU Boulder-based investigators with others at Colorado State University, the Los Alamos National Laboratory and elsewhere.”