For Zoom Link please contactÌýddelreyfernandez@uwaterloo.caÌýÌý
Speaker
Professor Traian Iliescu, Virginia Tech Department of Mathematics
Title
Reduced Order Models for Turbulent Flows
Abstract
In this talk, I will survey reduced order model (ROM) closures andÌýstabilizations for under-resolved turbulent flows. Over the pastÌýdecade, several closure and stabilization strategies have beenÌýdeveloped to tackle the ROM inaccuracy in the convection-dominated,Ìýunder-resolved regime, i.e., when the number of degrees of freedom isÌýtoo small to capture the complex underlying dynamics. I will presentÌýregularized ROMs, which are stabilizations that employ spatialÌýfiltering to alleviate the spurious numerical oscillations generallyÌýproduced by standard ROMs in the convection-dominated, under-resolvedÌýregime. I will also survey three classes of ROM closures, i.e.,Ìýcorrection terms that increase the ROM accuracy: (i) functionalÌýclosures, which are based on physical insight; (ii) structuralÌýclosures, which are developed by using mathematical arguments; andÌý(iii) data-driven closures, which leverage available data. ThroughoutÌýmy talk, I will highlight the impact made by data on classicalÌýnumerical methods for fluid flows over the past decade. I will alsoÌýemphasize the role played by physical constraints in data-drivenÌýmodeling of ROM closures and stabilizations."