Three‐dimensional large eddy simulation of wave characteristics of liquid film flow in a spinning disk reactor

Abstract

The waves of liquid film flow play an important role on the process intensification in spinning disk reactors (SDRs). However, the mechanism of wave formation was still unclear. In this work, a three‐dimensional large eddy simulation was developed to investigate the mechanism, as well as the characteristics of waves in the SDR. Agreed with the imaging results, different wave patterns were identified as: smooth film, concentric, and spiral waves in spreading direction; sine‐like and pulse‐like waves in fluctuating direction. The radial and tangential relative movements among the layers of liquid film were found to dominate the formation of different wave patterns. Local average film thickness (havg) and local wave amplitude (Δh) ranged from 0 to 500 μm and 0 to 200 μm, respectively. The waves can improve the turbulent intensity and enlarge the specific surface area, resulting in the intensification of transfer processes.

Dynamics of liquid dispersion in a rotating packed bed with single‐layer wire mesh

“…In the past decade, CFD simulation has played an essential role in the hydrodynamics study in RPBs, mainly to provide the hydrodynamic characteristics that are difficult to obtain by experimental methods. [37][38][39] In this study, the velocity components were crucial to determining the position and length of the liquid ligaments, which were challenging to obtain limited by the view and depth of highspeed photography. Therefore, the liquid dispersion under different operating conditions and impact positions was also obtained by CFD simulation to provide the velocity components of the liquid flow.…”

Determination of Liquid Residence Time Characteristics in Spinning Disk Reactors via a Computational Approach

“…Figure displays the geometric domain and grids of the 3D simulation of the RTD, taking SDR with CS as an example. The computational domain was set to one-quarter of the disk with double periodic boundaries at the sides (with a periodic angle of 90°) . The computational domain was meshed with structured hexahedral grids.…”

“…The flow behavior in the SDR was regarded as Newtonian, incompressible, and gas–liquid dual-phase flow. The volume of fluid (VOF) model was recognized as one of the most suitable multiphase models in the simulation of rotating devices, such as RPBs, rotating drum reactors, and SDRs . In the simulation, the VOF model was applied to describe gas–liquid multiphase flow, the shear-stress transport (SST) k –ω model was employed to obtain the pressure and velocity field, and the species transport model was activated to solve the concentration field of the injected tracer.…”

“…The computational domain was set to one-quarter of the disk with double periodic boundaries at the sides (with a periodic angle of 90°). 33 The computational domain was meshed with structured hexahedral grids. The RTD features, including the RTD curves, mean residence time, and dimensionless variance, were computed for different grid resolutions of 5, 10, 15, and 20 million.…”

Open Balance Point and Dry Pressure Drop of a Rectangular Float Valve Tray: Experiment and CFD Simulation

“…Its formulation is as follows: where ν t represents the turbulent kinematic viscosity, Δ f represents the filter scale, S ij represents the deformation tensor of the resolved field, g ij represents the velocity gradient tensor, δ ij represents Kronecker symbol, and Δ x represents the grid size − …”