(537c) Development of Particle Stress Model for MP-PIC Approach

Computational Fluid Dynamics (CFD) - Discrete Element Method (DEM) simulations are widely used to investigate gas-solid flow behavior in fluidized beds. These flows manifest dynamic meso-scale structures that span a wide range of spatial and temporal scales. These structures can be resolved by CFD-DEM simulations in small computational domains. However, the computational cost to resolve them in simulations of flows in large industrial units is prohibitive, where coarse-grained simulation approaches such as CFD-DPM (discrete parcel method) and MP-PIC (multi-phase particle-in-cell) are more viable [1,2,3]. In these coarse-grained simulations, only a small number of representative particles (a.k.a. “parcels”) are simulated and particle-particle interaction is treated via tracking collisions between particles [4] or a physically reasonable particle phase stress model [2,3]. In previous studies of our group [5,6], we proposed the coarse-grained fluid-particle drag relation for coarse CFD-DEM/DPM and MP-PIC simulations of industrial scale gas-particle flows. The goal of the present study is to provide the particle stress model for coarse MP-PIC simulations. We first performed highly resolved CFD-DEM simulations of gas-fluidization of mono-disperse particles in periodic domains at various solid volume fractions. By following the particle coarsening methodology given by [6], the results are analyzed to formulate an effective particle phase stress model. This model is then assessed in a posteriori manner through crossing jets and Taylor-Green vortex flow test cases. 

References

[1] M. Sakai, H. Takahashi, C.C. Pain, J. Latham, and J. Xiang, “Study on a large-scale discrete element model for fine particles in a fluidized bed” Adv. Powder Technol., 23 (2012).

[2] D. M. Snider, “An Incompressible Three-Dimensional Multiphase Particle-in-Cell Model for Dense Particle Flows”, J. Comp. Phys., 170, 523 (2001).

[3] P. J. O’Rourke, and D.M. Snider, “An improved collision damping time for MP-PIC calculations of dense particle flows with applications to polydisperse sedimenting beds and colliding particle jets”, Chem. Eng. Sci., 65, 6014 (2010). 

[4] N.A. Patankar, D.D. Joseph, “Lagrangian numerical simulation of particulate flows”, Int. J. of Multiphase Flow, 27, (2001).

[5] S. Radl, S. Sundaresan. "A drag model for filtered Euler–Lagrange simulations of clustered gas–particle suspensions." Chem. Eng. Sci. , 117, (2014).

[6] A. Ozel,  S. Radl, S. Sundaresan, ‘Effective Drag Model for Euler-Lagrange Simulations of Gas-Fluidized Beds’, AIChE Annual Meeting, Atlanta, Georgia, (2014).