Andrew Bragg

Associate Professor of Civil and Environmental Engineering

My intellectual interests and passions revolve around the desire to understand and predict the beautifully complex, enigmatic motion of turbulent flows, and their role in natural and engineered systems. The environment provides one of the richest settings motivating research on this topic, with far reaching implications for understanding atmospheric clouds, oceans, global warming, among many others. To address the profound complexity of turbulence I utilize methods from applied mathematics, statistical and theoretical physics, and high-performance computing. I also work closely with experimentalists, being convinced that a multifaceted, collaborative approach is required for significant progress on this very challenging subject.

Turbulent flows are inherently multiscale, and in environmental contexts they involve motion on spatial scales ranging from kilometers down to micrometers. Large-scale numerical simulations of environmental flows cannot resolve all of the scales, and so the unresolved scales must be parametrized. However, the nonlinear physics of the unresolved processes are often poorly understood, leading to great uncertainty in their parameterizations. This challenge is a key motivation for my own research, namely to understand the nonlinear physics of these small-scale processes and then to develop models that capture them for use in large-scale numerical models.


Before joining the Duke University faculty, Dr. Bragg was a postdoctoral associate in the Applied Mathematics and Plasma Physics Group at the Los Alamos National Laboratory. Prior to that, he was a postdoctoral associate in the Sibley School of Mechanical and Aerospace Engineering at Cornell University. Dr. Bragg obtained his PhD in Theoretical Fluid Dynamics from Newcastle University in England.

Appointments and Affiliations

  • Associate Professor of Civil and Environmental Engineering

Contact Information

Education

  • Ph.D. Newcastle University (United Kingdom), 2012

Research Interests

Physics and modeling of turbulence and turbulent transport; theoretical and computational fluid dynamics; applied mathematics.

Awards, Honors, and Distinctions

  • National Science Foundation CAREER award. CBET Fluid Dynamics. 2021
  • EUROMECH Young Scientist Award, given at the 16th European Turbulence Conference at KTH in Stockholm. European Mechanics Society. 2017

Courses Taught

  • CEE 690: Advanced Topics in Civil and Environmental Engineering
  • CEE 501: Applied Mathematics for Engineers
  • CEE 301L: Fluid Mechanics

In the News

Representative Publications

  • Hessenkemper, Hendrik, Andrew D. Bragg, Dirk Lucas, and Tian Ma. “Lagrangian tracking reveals competing influences of clustering and turbulence on the rise velocity of bubble swarms.” Proceedings of the National Academy of Sciences of the United States of America 122, no. 48 (December 2025): e2518309122. https://doi.org/10.1073/pnas.2518309122.
  • Grace, A. P., T. Berk, A. D. Bragg, and D. H. Richter. “Effects of settling on inertial particle slip velocity statistics in wall-bounded flows.” Journal of Fluid Mechanics 1015 (August 1, 2025). https://doi.org/10.1017/jfm.2025.10326.
  • Huang, G., H. Hessenkemper, S. Tan, R. Ni, A. Sommer, A. D. Bragg, and T. Ma. “Taylor dispersion of bubble swarms rising in quiescent liquid.” Journal of Fluid Mechanics 1014 (July 10, 2025). https://doi.org/10.1017/jfm.2025.10316.
  • Ma, Tian, Shiyong Tan, Rui Ni, Hendrik Hessenkemper, and Andrew D. Bragg. “Kolmogorov Scaling in Bubble-Induced Turbulence.” Physical Review Letters 134, no. 24 (June 2025): 244001. https://doi.org/10.1103/v9mh-7pw1.
  • Katul, G., A. Bragg, I. Mammarella, H. Liu, Q. Li, and E. Bou-Zeid. “Gas Transfer Across Air-Water Interfaces in Inland Waters: From Micro-Eddies to Super-Statistics.” Water Resources Research 60, no. 11 (November 1, 2024). https://doi.org/10.1029/2023WR036615.