Multiscale multiphase flow simulations using interface capturing and Lagrangian particle tracking

Abstract

Numerical simulations of multiphase flows with both interfaces and discrete particles are challenging because they possess a wide range of length and time scales. Meanwhile, the volume of fluid (VOF) method is suitable for resolving the interface while the discrete particle model (DPM) under the Lagrangian frame better simulates unresolvable particles, a multiscale VOF-DPM combined model is urgently needed for multiscale multiphase flows. The present work implements a VOF-DPM solver that includes a two-way transition algorithm to model the transformation between discrete and continuous phases for bubbles or droplets using OpenFOAM. The interface-capturing scheme in the solver is based on the interIsoFoam solver, which supports the geometric reconstruction of the interface and adaptive mesh refinement (AMR). A connected component labeling (CCL) approach is used for particle detection and VOF-to-DPM transition for discrete bubbles or droplets produced by interface breakup. Conversely, a DPM-to-VOF transition algorithm for particles touching the interface is incorporated to achieve a two-way transition. In addition, phase change modeling between continuous phases and bubble dynamic modeling for cavitating flow cases are also implemented in the solver. Test simulations are performed for validation, including the gas-liquid two-phase dam break and cavitating flow in a convergent-divergent test section. The results demonstrate that the solver is reasonably accurate and can adequately represent the complex phase structure, including the interface and discrete particles.

Simulation of phase change during the freezing of unsaturated porous media by using a coupled lattice Boltzmann model

“…This method is widely used to solve multiphase flow problems at different scales (Lewis et al , 1989). In the previous works, different approaches have been supported to numerically calculate multiphase flows, including phase transition and multiphase flows (Li et al , 2022; Sattarov et al , 2018). Despite the increasing number of studies on the above-mentioned flows, modeling two-phase flows with dynamic interfaces still cannot be described well due to the coupling of many influential factors, such as surface tension (Safari et al , 2013).…”

LES investigation of the wavy leading edge effect on cavitation noise

“…Cavitation [1] , [2] is a complex and multi-phase physical phenomenon that occurs when the local fluid pressure drops lower than saturated vapor pressure. Hydrodynamic cavitation is common in fluid machinery, such as hydrofoils [3] , [4] , [5] , [6] , [7] , marine propellers [8] , venturi tubes [9] , [10] , [11] , water treatment reactor [12] , [13] , [14] .…”

ANN based surrogate model for key Physico-chemical effects of cavitation

“…Several attempts have been done for developing such models which may be broadly classified into (a) simplified one-dimensional (1D) models based on Rayleigh-Plasset equations or their variants (see for example, Pandit et al [4] ) and (b) Multi-dimensional CFD based models (see for example, Orthaber et al [5] using volume of fluid approach or Shan et al [6] using lattice Boltzmann approach). In recent years, several attempts of developing multi-scale models of cavitating flows have been made (see for example, [7] , [8] , [9] ). However, the focus in such multi-scale models is on simulating overall flow characteristics rather than capturing details of cavity collapse.…”