336 citations · 1.5k across the 38 of their papers we have counts for
14 papers · 1 filter
Extreme firebrand transport by atmospheric waves in wildfires
Mohammad Farazmand
In wildfires, burning pieces of ember-firebrands-are carried downstream by wind. At the time of landing, these firebrands can start secondary fires far away from the main burning u…
Tensor-based flow reconstruction from optimally located sensor measurements
Mohammad Farazmand, Arvind K. Saibaba
Reconstructing high-resolution flow fields from sparse measurements is a major challenge in fluid dynamics. Existing methods often vectorize the flow by stacking different spatial…
Vortex boundaries as barriers to diffusive vorticity transport in two-dimensional flows
Stergios Katsanoulis, Mohammad Farazmand, Mattia Serra +1
We put forward the idea of defining vortex boundaries in planar flows as closed material barriers to the diffusive transport of vorticity. Such diffusive vortex boundaries minimize…
Closed-loop adaptive control of extreme events in a turbulent flow
Mohammad Farazmand, Themistoklis P. Sapsis
Extreme events that arise spontaneously in chaotic dynamical systems often have an adverse impact on the system or the surrounding environment. As such, their mitigation is highly…
Surface waves enhance particle dispersion
Mohammad Farazmand, Themistoklis Sapsis
We study the horizontal dispersion of passive tracer particles on the free surface of gravity waves in deep water. For random linear waves with the JONSWAP spectrum, the Lagrangian…
Are extreme dissipation events predictable in turbulent fluid flows?
Patrick J. Blonigan, Mohammad Farazmand, Themistoklis P. Sapsis
We derive precursors of extreme dissipation events in a turbulent channel flow. Using a recently developed method that combines dynamics and statistics for the underlying attractor…
Variational Lagrangian formulation of the Euler equations for incompressible flow: A simple derivation
Mohammad Farazmand, Mattia Serra
In 1966, Arnold [1] showed that the Lagrangian flow of ideal incompressible fluids (described by Euler equations) coincide with the geodesic flow on the manifold of volume preservi…
Relative periodic orbits form the backbone of turbulent pipe flow
Nazmi Burak Budanur, Kimberly Y. Short, Mohammad Farazmand +2
Chaotic dynamics of low-dimensional systems, such as Lorenz or Rössler flows, is guided by the infinity of periodic orbits embedded in their strange attractors. Whether this also b…
A Critical Comparison of Lagrangian Methods for Coherent Structure Detection
Alireza Hadjighasem, Mohammad Farazmand, Daniel Blazevski +2
We review and test twelve different approaches to the detection of finite-time coherent material structures in two-dimensional, temporally aperiodic flows. We consider both mathema…
A variational approach to probing extreme events in turbulent dynamical systems
Mohammad Farazmand, Themistoklis P. Sapsis
Extreme events are ubiquitous in a wide range of dynamical systems, including turbulent fluid flows, nonlinear waves, large scale networks and biological systems. Here, we propose…
Optimal initial condition of passive tracers for their maximal mixing in finite time
Mohammad Farazmand
The efficiency of a fluid mixing device is often limited by fundamental laws and/or design constraints, such that a perfectly homogeneous mixture cannot be obtained in finite time.…
An adjoint-based approach for finding invariant solutions of Navier-Stokes equations
Mohammad Farazmand
We consider the incompressible Navier--Stokes equations with periodic boundary conditions and time-independent forcing. For this type of flow, we derive adjoint equations whose tra…
Defining Coherent Vortices Objectively from the Vorticity
George Haller, Alireza Hadjighasem, Mohammad Farazmand +1
Rotationally coherent Lagrangian vortices are formed by tubes of deforming fluid elements that complete equal bulk material rotation relative to the mean rotation of the deforming…
Symmetry reduction in high dimensions, illustrated in a turbulent pipe
Ashley P. Willis, Kimberly Y. Short, Predrag Cvitanović
Equilibrium solutions are believed to structure the pathways for ergodic trajectories in a dynamical system. However, equilibria are atypical for systems with continuous symmetries…