Overview
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.
Current Appointments & Affiliations
Recent Publications
Effects of settling on inertial particle slip velocity statistics in wall-bounded flows
Journal Article Journal of Fluid Mechanics · August 1, 2025 Developing reduced-order models for the transport of solid particles in turbulence typically requires a statistical description of the particle-turbulence interactions. In this work, we utilize a statistical framework to derive continuum equations for the ... Full text CiteKolmogorov Scaling in Bubble-Induced Turbulence.
Journal Article Physical review letters · June 2025 Experiments using 3D Lagrangian tracking are used to investigate Kolmogorov scaling below the bubble size in bubble-induced turbulence (BIT). Second- and third-order structure functions reveal approximate Kolmogorov scaling for homogeneous bubble swarms. A ... Full text CiteGas Transfer Across Air-Water Interfaces in Inland Waters: From Micro-Eddies to Super-Statistics
Journal Article Water Resources Research · November 1, 2024 In inland water covering lakes, reservoirs, and ponds, the gas exchange of slightly soluble gases such as carbon dioxide, dimethyl sulfide, methane, or oxygen across a clean and nearly flat air-water interface is routinely described using a water-side mean ... Full text CiteRecent Grants
Development and application of a wall model for the dust-laden atmospheric boundary layer
ResearchPrincipal Investigator · Awarded by University of Notre Dame · 2022 - 2026CAREER: Sheared stratified turbulence: novel mechanisms and models of complex wave-vortex interactions that impact our environment
ResearchPrincipal Investigator · Awarded by National Science Foundation · 2021 - 2025Implications of heterogeneity-aware land-atmosphere coupling in the predictability of precipitation extremes
ResearchCo-Principal Investigator · Awarded by National Oceanic and Atmospheric Administration · 2022 - 2024View All Grants