{Seminar} @ CDS: #202: 11th June: “Large/Small Eddy Simulations: A practical method for high-fidelity simulations of large Reynolds number turbulent flows.”


11 Jun 24    
10:00 AM - 11:00 AM

Event Type

Department of Computational and Data Sciences
Department Seminar

Speaker : Arnab Moitro, PhD Candidate, University of Connecticut, USA
Title : Large/Small Eddy Simulations: A practical method for high-fidelity simulations of large Reynolds number turbulent flows.
Date & Time : June 11, 2024, 10:00 AM
Venue : # 202, CDS Classroom

Turbulent flows are ubiquitously found in nature and engineering systems and are characterized b chaotic fluctuations spanning a wide range of interacting scales. Numerical simulation of turbulent flows from first principles using direct numerical simulations (DNS) is computationally expensive and restricted to moderate Reynolds numbers in idealized domains, decoupled from any realistic large-scale flow. On the other hand, lower fidelity techniques such as large eddy simulations (LES), used for modelling practical and natural systems rely on closure models that make multiple assumptions which are often violated and require prior knowledge of the flow. In this talk, a novel multi-fidelity approach will be discussed which couples a lower-fidelity, unresolved, time-dependent calculation of the entire system (LES), and a high-fidelity, fully resolved simulation of a sub-region of interest of the LES. The method is formulated in physical space, makes no assumptions of equilibrium, isotropy, initial or boundary conditions of the underlying flow, and can potentially be used for any regime whose properties are unknown. A priori and posteriori tests of both steady and unsteady homogeneous, isotropic turbulence are used to demonstrate the method accuracy in recovering turbulence properties, including spectra, high order moments of velocity gradients, and probability density functions of the intermittent quantities. The method is shown to achieve DNS-level accuracy with three orders of magnitude reduction in computational cost, thus opening the possibility to study high Reynolds number flow regimes.

Arnab Moitro is a PhD candidate in the School of Mechanical, Aerospace and Manufacturing Engineering at the University of Connecticut. Prior to this, he received his dual degree (BTech+MTech) from Indian Institute of Technology, Madras and also worked as a research associate at Indian Institute of Science, Bangalore. He will be joining Newcastle University as a post-doctoral research associate in July 2024. His work focusses on high- and multi-fidelity simulations and modelling of turbulent reacting and non-reacting flows.

Host Faculty: Dr. Konduri Aditya