Nav: Home

Army scientists create new technique for modeling turbulence in the atmosphere

August 07, 2018

Army researchers have designed a computer model that more effectively calculates the behavior of atmospheric turbulence in complex environments, including cities, forests, deserts and mountainous regions.

This new technology could allow Soldiers to predict weather patterns sooner using the computers at hand and more effectively assess flight conditions for aerial vehicles on the battlefield.

Turbulence may be invisible to the naked eye, it is always present around us in the air in the form of chaotic changes in velocity and pressure.

Traditional computational fluid dynamics methods of analyzing atmospheric turbulence treat the fluid as a continuum, solving the nonlinear Navier-Stokes differential equations that are involved.

However, calculating the turbulence in the planetary boundary layer, the lowest layer of the atmosphere, can be difficult due to how the presence of trees, tall buildings and other aspects of the landscape directly influences its behavior.

TCFD methods must account for all effects of the neighboring points surrounding the target, which creates an immense computational load that is very difficult to implement efficiently on modern parallel architectures, such as Graphics Processing Unit accelerators.

As a result, these methods often face challenges when confronted with more intricate environments due to limitations in treating complex surface boundaries.

In an attempt to search for an alternative approach, a team of U.S. Army Research Laboratory scientists led by Dr. Yansen Wang turned to the field of statistical mechanics for ideas.

What they found was the Lattice-Boltzmann method, a technique used by physicists and engineers to predict fluid behavior on a very small scale.

"The Lattice-Boltzmann method is normally used to predict the evolution of a small volume of turbulence flows, but it has never been used for an area as large as the atmosphere," Wang said. "When I read about it in a research paper, I thought that it could be applied to not just a small volume of turbulence but also atmospheric turbulence."

Unlike TCFD methods, the LBM treats the fluid like a collection of particles instead of a continuum and has been widely used in fluid simulation to accurately portray fluid dynamics.

Wang and his team determined that this new approach could accurately model atmospheric turbulence while requiring much less computation than if they had solved for the NS differential equations.

This fundamental change essentially allowed them to disregard a huge chunk of the neighboring points on the grid model, cutting the number of neighboring behaviors to account for and significantly lessening the computational load.

As a result of their investigation, the researchers used the newly developed multi-relaxation-time Lattice-Boltzmann method to create an advanced Atmospheric Boundary Layer Environment model, which specifically treated highly turbulent flow in complex and urban domains.

This marks the first time that an advanced MRT-LBM model has been used to model the atmosphere.

The newly developed ABLE-LBM model paves the way for a highly-versatile approach to atmospheric boundary layer flow prediction.

In addition to providing faster operating speed and simpler complex boundary implementation, this approach is intrinsically parallel and thus compatible with modern parallel architectures, making it a potentially viable modeling method on tactical compute platforms for the U.S. military.

"On the battlefield, you want atmospheric turbulence data quickly but you don't necessarily have any supercomputers on hand," Wang said. "However, you do have modern computer architecture with thousands of processors that make computing fast if the algorithm is appropriate. With the ABLE-LBM, you can use those modern computer architectures to compute turbulence on the battlefield without having to connect to a high performance computing center."

The development of the ABLE-LBM model has significant ramifications on many other aspects of Army operations besides weather forecast.

Atmospheric turbulence can significantly affect the behavior of optic and acoustic waves, which directly impact what Soldiers can see and hear.

It can act as an important factor in reconnaissance and change the path that a laser travels or how sounds are emitted from a system.

Small unmanned aerial systems are also at the mercy of turbulence vortices, which can occur when a gust of wind hits a building.

Knowing how the turbulence will behave can help sUAS avoid collisions and even take advantage of existing updrafts to fly without their propellers to save energy.

Potential applications can also be found outside the military in civilian life.

Better knowledge of boundary layer turbulence can assist in civil planning in both preparation and emergency response when dealing with chemical spills, industrial fires and other man-made or natural disasters.

"Many people are interested in applying this method in various fields," Wang said. "This technique has paved a new way to model atmospheric turbulence. Our research was the first to set the path for this new direction, so we have a lot of proving to do."
Details of this breakthrough are described in the paper, "Simulation of stratified flows over a ridge using a lattice-Boltzmann model" by Yansen Wang, Benjamin T. MacCall, Christopher M. Hocut, Xiping Zeng and Harindra J. S. Fernando in the journal Environmental Fluid Mechanics (available online at

The results and methodology of ABLE-LBM were presented at the American Meteorological Society Mountain Meteorology Conference June 29 in Santa Fe, New Mexico.

The U.S. Army Research Laboratory is part of the U.S. Army Research, Development and Engineering Command, which has the mission to ensure decisive overmatch for unified land operations to empower the Army, the joint warfighter and our nation. RDECOM is a major subordinate command of the U.S. Army Materiel Command.

U.S. Army Research Laboratory

Related Behavior Articles:

Fishing for a theory of emergent behavior
Researchers at the University of Tsukuba quantified the collective action of small schools of fish using information theory.
How synaptic changes translate to behavior changes
Learning changes behavior by altering many connections between brain cells in a variety of ways all at the same time, according to a study of sea slugs recently published in JNeurosci.
I won't have what he's having: The brain and socially motivated behavior
Monkeys devalue rewards when they anticipate that another monkey will get them instead.
Unlocking animal behavior through motion
Using physics to study different types of animal motion, such as burrowing worms or flying flocks, can reveal how animals behave in different settings.
AI to help monitor behavior
Algorithms based on artificial intelligence do better at supporting educational and clinical decision-making, according to a new study.
Increasing opportunities for sustainable behavior
To mitigate climate change and safeguard ecosystems, we need to make drastic changes in our consumption and transport behaviors.
Predicting a protein's behavior from its appearance
Researchers at EPFL have developed a new way to predict a protein's interactions with other proteins and biomolecules, and its biochemical activity, merely by observing its surface.
Spirituality affects the behavior of mortgagers
According to Olga Miroshnichenko, a Sc.D in Economics, and a Professor at the Department of Economics and Finance, Tyumen State University, morals affect the thinking of mortgage payers and help them avoid past due payments.
Asking if behavior can be changed on climate crisis
One of the more complex problems facing social psychologists today is whether any intervention can move people to change their behavior about climate change and protecting the environment for the sake of future generations.
Is Instagram behavior motivated by a desire to belong?
Does a desire to belong and perceived social support drive a person's frequency of Instagram use?
More Behavior News and Behavior Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Sound And Silence
Sound surrounds us, from cacophony even to silence. But depending on how we hear, the world can be a different auditory experience for each of us. This hour, TED speakers explore the science of sound. Guests on the show include NPR All Things Considered host Mary Louise Kelly, neuroscientist Jim Hudspeth, writer Rebecca Knill, and sound designer Dallas Taylor.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

Kittens Kick The Giggly Blue Robot All Summer
With the recent passing of Ruth Bader Ginsburg, there's been a lot of debate about how much power the Supreme Court should really have. We think of the Supreme Court justices as all-powerful beings, issuing momentous rulings from on high. But they haven't always been so, you know, supreme. On this episode, we go all the way back to the case that, in a lot of ways, started it all.  Support Radiolab by becoming a member today at