UMD Researchers Identify Structure of Blue Whirls

UMD Researchers Identify Structure of Blue Whirls

Bookmark and Share


“Blue whirls”—small, spinning blue flames that produce almost no soot when they burn—have attracted great interest since their discovery in 2016, in part because they represent a potential new avenue for low-emission combustion.

Now, a team of researchers at the University of Maryland and Texas A&M University have identified how these intriguing whirls are structured. Their findings were published in the peer-reviewed journal Science Advances on August 12, 2020.

The team includes now-graduated UMD aerospace engineering PhD students Joseph D. Chung and Xiao Zhang, working with Professor Elaine S. Oran, who is TEES Eminent Research Professor at Texas A&M University and previously Glenn L. Martin Professor at UMD’s A. James Clark School of Engineering, and Dr. Carolyn R. Kaplan of the Department of Aerospace Engineering at UMD.

Using high-performance computing methods at the University of Maryland’s Deepthought2 cluster and other computer systems, the researchers showed that a blue whirl is composed of three different flames—a diffusion flame and a premixed rich and lean flame—all of which meet in a fourth structure, a triple flame that appears as a whirling blue ring. The researchers also found that vortex breakdown—a fluid instability that occurs in swirling flows--enables the blue-whirl structure to emerge.

“The flame and flow structure revealed by the simulations serves as a fundamental base to further investigate how to create the blue whirl in a more controlled way,” said Zhang. “It leads pathways to answering more complex questions.”

“Examples of such questions are: How to create blue whirls in different scales? Can we bypass the transitional, sooty, dangerous fire whirl stage and create the stable and clean blue whirl directly? The newly developed algorithms and models also provide great exploring tools to find these answers,” Chung said.

Blue whirls were initially discovered in 2016 by Oran, working with Professor Michael Gollner, previously of the Fire Protection Engineering Department and now at University of California, Berkeley, and Professor Huahua Xiao, previously in the Department of Aerospace Engineering at UMD and now at the University of Science and Technology in Hefei, China. At the time, they were investigating the behavior of a known phenomenon—the fire whirl, also known as fire tornado—when it occurs on a water base.

“Blue whirls evolve from traditional yellow fire whirls,” Oran said. “The yellow color is due to radiating soot particles, which form when there is not enough oxygen to burn the fuel completely.”

“Blue in the whirl indicates there is enough oxygen for complete combustion, which means less or no soot, and is therefore a cleaner burn. We now know that blue whirl will burn all of the fuel available as it exits a burner or from a surface.”

Support for the new study was provided by grants from the National Science Foundation, the Army Research Office, the Army Research Laboratory, and the Minta Martin Endowment Funds in the Department of Aerospace Engineering at the University of Maryland, and the TEES Eminent Professorship at TAMU. Computations used in the new study were performed on the University of Maryland, Deepthought2 cluster, Thunder from the Air Force Research Laboratory, and Stampede2 from the Texas Advanced Computing Center.

 

August 14, 2020


Prev   Next



Current Headlines

University of Maryland Research Enterprise Ranked Among Top 10 Publics in NSF Higher Education R&D Survey

QTC Awarded $1.5M from the Department of Energy for Research on Quantum Diamond Magnetometers

A Hole New Perspective on Brood X

$1.4M Grant to Expand Enslaved.org

CBCB Researchers Develop Tool that Makes Reconstructing Microbial Genomes Easier

Conservation Criminology for a Troubling Trade

English Department To Collaborate on Three Antiracism Publications

Gabriel, Brubaker developing game theory water market models for river users

News Resources

Return to Newsroom

Search News

Archived News

Events Resources

Events Calendar

Additional Resources

UM Newsdesk

Faculty Experts

Connect

social iconsFacebookTwitterLinkedInResearch News RSS Feed
Office of Technology Commercialization
2130 Mitchell Building
7999 Regents Dr.
University of Maryland
College Park, MD 20742

Phone: 301-405-3947  |  Fax: 301-314-9502
Email: umdtechtransfer@umd.edu

© Copyright 2013 University of Maryland

Did You Know

UMD's Neutral Buoyancy Research Facility, which simulates weightlessness, is one of only two such facilities in the U.S.