| Wed February 10th 2016 16:30 – 17:00 ZH286 | Seminar | Challenges in numerical simulations of two-phase turbulent flows and an insight into drag reduction in bubbly Taylor-Couette Vamsi Spandan |
Details:Multiphase turbulent flows are widely present in naturally occurring phenomena (e.g. cloud formation, plankton dispersion in sea, blood flow etc.) and are also relevant in many industrial applications (e.g. fuel sprays, emulsification, drag reduction etc.). While the interaction between multiple fluid phases makes the underlying physics very interesting and rich, on the other hand theoretical and numerical modelling of such flows is extremely challenging due to the wide range of length and time scales involved. In this talk I will first briefly discuss the challenges in large scale computations of two-phase turbulent flows and the techniques employed to overcome them. Next, I will employ one such technique, namely Euler-Lagrange (EL) to study the phenomenon of drag reduction in a turbulent Taylor-Couette system. We study the influence of buoyancy of sub-Kolmogorov spherical bubbles tracked in a Lagrangian manner on the dynamics of turbulent carrier flow which is computed using Direct Numerical Simulations (DNS). In addition we improve the conventional EL technique by coupling it with a sub-grid phenomenological model to study the dynamics of deformation and orientation properties of anisotropic (here ellipsoidal) dispersed phase. | ||
