Coupled smoothed particle hydrodynamics and discrete element method for simulating coarse food particles in a non-Newtonian conveying fluid

A Lagrangian particle-based numerical framework based on smoothed particle hydrodynamics (SPH) coupled with the discrete element method (DEM) was used to simulate the flow behaviour of coarse food particles in a non-Newtonian conveying fluid in a horizontal pipe. Nearly-neutrally buoyant nearly-spherical calcium-alginate particles were used as model food particles. The capability of the SPH-DEM methodology was successfully validated in non-Newtonian single-phase as well as in two-phase particle-liquid flows by comparing the local phase velocity flow field, radial particle distribution and particle passage times with experimental Lagrangian measurements obtained by a technique of positron emission particle tracking. The simulations also yielded accurate predictions of flow pressure drop. In addition, detailed information was afforded on local particle spin, fluid pressure and carrier fluid vorticity. The results demonstrate the high capability of the proposed numerical framework to predict the complex features of complex particle-liquid flows in pipes.