Direct numerical simulations and experiments of a pseudo-2D gas-fluidized bed

Scale‐dependent nonequilibrium features in a bubbling fluidized bed

“…In greater detail, the PDF of particle velocity shows a non-Gaussian shape in a vibro-fluidized bed, where energy was injected from vibrating boundaries and dissipated through particle collisions. 28,[45][46][47][48][49] For a molecular equilibrium system, continuum hypothesis can be used to attach a definite meaning to the notion of local values of various macroscopic variables such as the density, velocity and temperature and these values are continuous functions of position and time. 34,38 The farther from the boundary, the more symmetrical is local PDF.…”

“…34,38 The farther from the boundary, the more symmetrical is local PDF. Most studies on this topic are based on simulation 28,48,49 and relevant experimental data are scarce. A skewed distribution and even a bimodal distribution can be found along vertical (driving) direction.…”

“…44 Besides PDF of particle velocity, other hydrodynamic quantities, like the granular density, velocity and granular temperature, also depend on spatio-temporal scales. 28,[45][46][47][48][49] For a molecular equilibrium system, continuum hypothesis can be used to attach a definite meaning to the notion of local values of various macroscopic variables such as the density, velocity and temperature and these values are continuous functions of position and time. 50 The meso-scale structures in fluidization, in forms of bubbles or clusters, prevent us to raise simple definitions on e.g.…”

“…the averaged velocity of particle and granular temperature. Most studies on this topic are based on simulation 28,48,49 and relevant experimental data are scarce.…”

Effect of granular temperature and solid concentration fluctuation on the gas-solid drag force: A CFD test

“…Therefore the model of Wylie et al (Wylie et al, 2003) was not tested here. As a final note, there are more DNS of gas-solid flow in real fluidized beds (Luo et al, 2016;Tang et al, 2016a), however, those studies are using rough particles, therefore, a rigorous comparison can be carried out only if a kinetic theory of rough particles has been implemented into the two-fluid model.…”