(653e) Experimental Investigation of Horizontal Air Jets in Semi-Circular, Gas-Solid Fluidized Bed

Experiments were undertaken at PSRI with the intent to provide a validation benchmark problem with characterized uncertainties for the coupled computational fluid dynamics–discrete element method (CFD-DEM) modeling approach. In this talk, we will focus on the first material studied: 6 mm plastic beads. For this material, the particle count in the system is roughly 60,000, making it amenable for direct comparison with CFD-DEM using today’s computational resources. The Geldard Group D particles are well characterized; particle size, shape, coefficients of restitution and kinetic friction are measured. The test section is a semi-circular bed approximately 12 inches in diameter. Additional fluidization is provided by two horizontal air jets which penetrate the unit near the flat, front face. The opposing jets are operated at one of two vertical locations. Moreover, uncertainties in each of the experimental parameters are quantified for use in formal uncertainty quantification (UQ) analyses. During operation, the bed pressure drop is measured with pressure taps in and above the bed. Additionally, high speed video (HSV) imaging of the front face is taken to record the dynamics of the particles in and near the jet regions. The HSV images are processed with an in-house particle tracking algorithm and time- and spatially- averaged. By producing a map of the particle Froude number (using 2-D velocity magnitude), we trace isolines of Fr = 0.15 which are used to calculate the jet penetration depths. In this manner, we report a quantity that can be compared in a straightforward manner with both CFD-DEM and TFM simulations. We show further how the interaction of the jets varies with separation distance by extending the jets into the domain. Finally, we will conclude by previewing additional materials studied in this unit—specifically, with smaller diameter particles and thus higher particle counts, we hope this validation set will grow with the increasing power of the CFD-DEM technology itself.