Seminars and Colloquia
Physics
Effects of viscoelasticity in fluids and living systems
Wed, Sep 25, 2019,
11:30 AM
at Seminar Hall 33, 2nd floor, Main Building
Dr. Anupam Gupta
Harvard University, USA
Abstract :
In this seminar, I will talk about the effects of viscoelasticity on passive fluid flows and active living system. It is well known that viscoelasticity affects the fluid flows significantly, in the turbulent flow they lead to dissipation reduction.
In the first part of my talk, I will discuss the effects of polymer additives in two-dimensional homogeneous, isotropic turbulence and this work focuses on studying the statistical properties using direct numerical simulations. The kinetics of the polymers is introduced using constitutive equations for viscoelastic fluids with finitely extensible non-linear elastic dumbbells with Peterlin’s closure (FENE-P). Our study reveals that the polymers have a significant effect on multiple scales of the turbulent flow affecting some of the physical quantities and their intermittent properties.
In the first part of my talk, I will discuss the effects of polymer additives in two-dimensional homogeneous, isotropic turbulence and this work focuses on studying the statistical properties using direct numerical simulations. The kinetics of the polymers is introduced using constitutive equations for viscoelastic fluids with finitely extensible non-linear elastic dumbbells with Peterlin’s closure (FENE-P). Our study reveals that the polymers have a significant effect on multiple scales of the turbulent flow affecting some of the physical quantities and their intermittent properties.
In the second part, I will discuss the mechanical regulation of shape deformation by matrix viscoelasticity in breast tissues. The shape change is one of the phenomena seen in cancerous tissue and the physical mechanism that allows this process to take place has not been clear. The synthetic extracellular matrix (ECM) are typically almost purely elastic. In contrast, the physiological ECM in various tissues, such as brain, liver, adipose tissue, and coagulated bone marrow, etc. are all viscoelastic. Most of the studies to date have focussed largely on elastic properties of ECM. Recently synthetic ECMs have been developed which closely mimic the natural viscoelastic ECMs. In this study, we are further looking into the role of such mechanical properties in inducing the malignant phenotype in normal mammary epithelium MCF10A cell line. Based on these experimental findings we have proposed a mathematical model to capture the qualitative results. This is the first mechanical model to capture this epithelial to mesenchymal transition by changing the viscoelastic properties of ECM.
