MAE Seminar: How Do Dispersed Inertial Particles Modify Turbulent Flows?
Distinguished Professor Emeritus
Department of Mechanical and Aerospace Engineering
Abstract: Turbulent flows laden with inertial particles are ubiquitous in nature (e.g., aerosols in clouds and dust storms on Earth and Mars) and in industrial applications (e.g., liquid fuel and pulverized coal sprays in combustion chambers). Experimental and numerical studies of these flows are quite challenging due to the wide spectra of length- and time-scales of the dispersed particles in addition to the spectra of scales intrinsic to the carrier fluid turbulence. The two-way and four-way nonlinear interactions between the dispersed particles and the turbulence result in complex multi-scale physical phenomena. The lecture focuses on the physical mechanisms of interactions between dispersed spherical particles and isotropic turbulence using Direct Numerical Simulation (DNS). Particles whose diameter is smaller than the Kolmogorov length scale are simulated as point particles. Larger particles with diameter of the order of Taylor microscale are fully resolved using the Immersed Boundary method. Some DNS results of fully resolved deformable liquid droplets in isotropic turbulence will be also presented.
Bio: Said Elghobashi is a Distinguished Professor Emeritus at the Department of Mechanical and Aerospace Engineering, UC Irvine. He is a member of the National Academy of Engineering, a fellow of the American Physical Society, the American Association for the Advancement of Science, and the American Society of Mechanical Engineers. The main objective of his research is to understand some of the fundamental properties of turbulence using the method of DNS. He received his M.S. from the University of Southern California and Ph.D. and D.Sc. from Imperial College, University of London.