This small Business Innovation Research Phase I project will demonstrate the feasibility of Large Eddy Simulation (LES) as a viable computational tool for the prediction of gas-particle flow phenomena. Present-day turbulence models use many ad-hoc procedures to represent turbulence fluctuations and also particle transport by these fluctuations. LES removes this empiricism by computing the dominant, unsteady, large scale turbulence. Unlike a Direct Simulation, it allows calculation at realistic Reynolds numbers and at a reasonable cost. We propose to extend this technique to include gas-solid flows. In Phase I, we will carry out a careful study of the role of LES (and sub-grid scale modeling for both fluid stress and velocity) in the context of particulate dispersion, mixing, collision and deposition. Particulate, turbulent flows in an isotropic and channel geometry are the two test cases chosen. Results will be validated by comparing LES with prior experimental and Direct Numerical Simulation (DNS) data. In Phase II, LES capabilities will be extended to Body-Fitted and Unstructured grids, needed to tackle complex geometries. The specific objectives of the Phase I study are two-fold: (i) develop and validate Gas-Particle Large Eddy Simulation tool; and (ii) assess the impact of LES on particulate phenomena such as dispersion, deposition and collision. The development of the LES tool for two-phase flows will have a deep and far-reaching impact on a staggeringly diverse list of areas ranging from chemical/pharmaceutical industry to environmental pollution control.
