GALCIT Colloquium

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 timescales of the dispersed particles in addition to the spectra of scales intrinsic to the carrier fluid turbulence. The twoway 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 incompressible isotropic turbulent flows using Direct Numerical Simulation (DNS). The computations have been performed on massively parallel high-performance supercomputers. 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.