Dynamics of elliptic particle sedimentation with thermal convection

Abstract

In this paper, a recently developed direct numerical simulation technique, the Finite Element Fictitious Boundary Method (FEM-FBM) [K. Walayat et al., “An efficient multi-grid finite element fictitious boundary method for particulate flows with thermal convection,” Int. J. Heat Mass Transfer 126, 452–465 (2018)], is used to simulate sedimentation of an elliptic particle with thermal convection. The momentum and temperature flow fields are coupled with the aid of Boussinesq approximation. The thermal and momentum interactions between solid and fluid phases are handled by using the fictitious boundary method (FBM). The continuity, momentum, and energy equations are solved on a fixed Eulerian mesh which is independent of flow features by using a multi-grid finite element scheme. Two validation tests are conducted to show the accuracy of the present method, and then the effects of thermal properties of fluid on the sedimentation of an elliptic particle are studied. It is demonstrated that the dynamics of hot elliptic particle sedimentation depend on the thermal diffusivity and thermal expansion of the fluid. A comparative study of the forces and torque acting on the hot, cold, and isothermal particle is reported. Moreover, different sedimentation modes of hot and cold elliptic particles are identified in an infinitely long channel. The mechanism of transitions of particle settling modes from tumbling to inclined and then to the horizontal mode is discovered. Also, we discovered a new sedimentation mode of the hot elliptic particle in cold fluid, i.e., the vertical mode. Furthermore, buoyancy effects for the catalyst particle are studied at different initial orientations.

Efficient FEM FBM for Simulation of Elliptic Particle Sedimentation with Thermal Convection

“…In [42], contributors analysed results convection of thermal on segments of an elliptic element when improving into impenetrable liquor utilizing multi-network FEM-FBM. The displayed system settles the warmth, force, and coherence conditions all the while.…”

“…In this paper, we motivated from the works reported in [40] and [42] to design the PSO construct multigrain FEM-FBM design to recreate the particulate streams with thermal convection.…”

“…The trading of vitality and force happens among fluid and particles during the interactions such as hydrodynamic forces, momentum interaction, energy interaction, and Bossiness approximation. The equations of such problems described in [40] [42]. To solve such problems related to interactions the solver model introduced in next section.…”

“…After presenting the PSO based multi-grid solver, next we have to present the model of Multi-grid PFEM-FBM solver. This multi-matrix invented limit technique depends on the PFEM foundation framework which covers the entirety computational domain as described in [40] [42]. Using the solver model, we further perform the computations to solve the problems related to hydrodynamic forces, torque, drag and lift coefficients, energy balance equations, dimensionless parameters which are used to investigate the dynamic sedimentation behaviour of particle with thermal [42].…”

“…The validation study presented to verify the effectiveness of proposed PFEM-FBM as compared to recent method FEM-FBM [42]. The validation is performed through the comparative analysis of simulated test cases in terms of maximum and minimum values to claim the effective implementation of energy balance equation as well as to claim effectiveness of proposed model.…”