Lagrangian Particle Tracking in Velocity-Vorticity Resolved Viscous Flows by Subdomain BEM

Abstract

A numerical study of particle motion in a cubic lid driven cavity is presented. As a computational tool, a boundary element based flow solver with a Lagrangian particle tracking algorithm is derived. Flow simulations were performed using an in-house boundary element based 3D viscous flow solver. The Lagrangian particle tracking algorithm is capable of simulation of dilute suspensions of particles in viscous flows taking into account gravity, buoyancy, drag, pressure gradient and added mass. The derived algorithm is used to simulate particle behaviour in a cellular flow field and in a lid driven cavity flow. Simulations of particle movement in a cellular flow field were used to validate the algorithm. The main goal of the paper was to numerically simulate the flow behaviour of spheres of different densities and different diameters, as experimentally observed in work of Tsorng et al.The study of slightly buoyant and non-buoyant particles in a lid driven cavity was aimed at discovering cases when particles leave the primary vortex and enter into secondary vortices, a phenomenon described in the work of Tsorng et al. A parametric study of this phenomenon was preformed. The presented computational results show excellent agreement with experiments, confirming the accuracy of the developed computational method.

Numerical modelling of skin tumour tissue with temperature-dependent properties for dynamic thermography

“…The main reason for choosing this method is its advanced treatment of boundary conditions, where Neumann boundary conditions are directly incorporated in the formulation without any additional approximation, which increases the accuracy of the numerical solution while the subdomain approach increases the computational speed. The subdomain approach has been discussed in detail by Ramšak andŠkerget [61,62], Ravnik et al [63,64], as well as in our previous work [65] and will be omitted in this paper. We already derived a BEM numerical scheme for solving 2D transient bioheat problems based on elliptic and parabolic fundamental solutions with great success [65].…”

Subdomain BEM formulations for the solution of bio-heat problems in biological tissue with melanoma lesions

“…The numerical technique adopted is the Boundary Element Method (BEM), which allows for simultaneous evaluation of temperature and heat flux. It should be noted that, in addition to an accurate solver, we are looking for speed of calculation prompting the use of the subdomain approach which was shown to be much faster than the classical BEM, see Ramšak andŠkerget [24,25] and Ravnik et al [26,27]. Thus, another aim of this paper is to find an efficient solver satisfying both the accuracy and the computational speed requirements.…”