Fluid Mechanics and Waves Seminar  Fall 2019
Seminars are held on Mondays from 2:30  3:30PM in Cullimore Hall, Room 611, unless noted otherwise.
Seminars are held on Mondays from 2:30  3:30PM in Cullimore Hall, Room 611, unless noted otherwise.
For questions about the seminar schedule, please contact Anand Oza.
To join the Fluid Mechanics and Waves seminar mailing list visit https://groups.google.com/a/njit.edu/forum/#!forum/mathfmws/join (Google Profile required). To join the mailing list without a Google Profile, submit the seminar request form.
Date  Speaker, Affiliation, Title, and Abstract  Host 

September 23 
Amir Sagiv, Department of Applied Physics and Applied Mathematics, Columbia University Prediction of Random and Chaotic Dynamics in Nonlinear Optics The prediction of interactions between nonlinear laser beams is a longstanding open problem. A traditional assumption is that these interactions are deterministic. We have shown, however, that in the nonlinear Schrodinger equation (NLS) model of laser propagation, beams lose their initial phase information in the presence of input noise. Thus, the interactions between beams become unpredictable as well. Not all is lost, however. The statistics of many interactions are predictable by a universal model. Computationally, the universal model is efficiently solved using a novel splinebased stochastic computational method. Our algorithm efficiently estimates probability density functions (PDF) that result from differential equations with random input. This is a new and general problem in numerical uncertaintyquantification (UQ), which leads to surprising results and analysis at the intersection of probability and approximation theory. 
Roy Goodman 
October 7 
Eduardo Corona Department of Mathematics, New York Institute of Technology A Fast Algorithmic Framework for Dense Rigid Body Suspensions in Stokes Flow The study of dense particulate suspensions is of great interest in fundamental science and technological applications; Often, the physical phenomenon of interest happens at scales much larger than the constituent particle sizes e.g. collective motion in bacterial suspensions or material selfassembly. We thus require scalable and robust simulation methods to produce valuable insights on these systems. 
Travis Askham 
October 21 
Scott Wunsch, Johns Hopkins University Internal Waves in Variable StratificationInternal waves are oscillatory motions of a densitystratified fluid. They are ubiquitous in Earth's oceans and atmosphere, transporting momentum and energy and playing an important role in ocean dynamics and climate. In varying stratification, internal waves transfer energy to harmonic modes. This nonlinear process may contribute to the transfer of internal wave energy from large to small scales in the ocean. This seminar will introduce basic concepts of internal wave propagation and explore harmonic generation in variable stratification using weakly nonlinear theory, laboratory experiment, and numerical simulation.

Yuannan Young 
November 18 
David Stein, Center for Computational Biology, Flatiron Institute HighAccuracy Simulations of Thousands of Deformable, Interacting, Active Droplets Coarsegrained continuum models of active fluids capture important aspects of selforganizing behavior seen in experiments while providing a computationally tractable basis for their simulation. Producing accurate solutions to these models is nevertheless challenging, and numerical schemes for their solution have been largely limited to simple, stationary geometries or lowaccuracy methods. In this talk, I will describe a spectrally accurate method for the simulation of active fluids in complex geometries, and show how to use this method to simulate deformable droplets of active fluids. When multiple drops are immersed in a Stokesian fluid, their interactions are captured through a robust and scalable boundary integral method, allowing for the simulation of thousands of such particles which may come into nearcontact with each other. We explore some of the emergent phenomenon that occurs with such large aggregates of active droplets. 
Anand Oza 
Updated: November 26, 2019