Problem of turbulent flow in porous media is studied numerically. General mathematical model is given with the time averaged macroscopic Navier-Stokes equations, as a turbulent model the macroscopic k-fÕ model is adopted. For the numerical solving of obtained set of partial differential equations the extended boundary element method (BEM) is used, also known as the boundary domain integral method (BDIM). All governing equations are transformed with use velocityvorticity formulation which separates the computational scheme into a kinematic and kinetic computational parts. Some initial test results of obtained numerical algorithm are presented.
COBISS.SI-ID: 14282518
In the present paper problem of natural convection in a cubic porous cavity is studied numerically, using an algorithm based on a combination of single domain and subdomain boundary element method (BEM). The modified Navier-Stokesequations (Brinkman-extended Darcy formulation with inertial term included) were adopted to model fluid flow in porous media, coupled with the energy equation using the Boussinesq approximation. The governing equations are transformed by the velocity-vorticity variables formulation which separates the computation scheme into kinematic and kinetic parts. The kinematics equation, vorticity transport equation and energy equation are solved by the subdomain BEM, while the boundary vorticity values, needed as a boundary conditions for the vorticity transport equation, are calculated by single domain BEM solution of the kinematics equation. Computations are performed for steady state cases, for a range of Darcy numbers from 10-6 to 10-1, and porous Rayleigh numbers ranging from 50 to 1000. The heat flux through the cavity and the flow fields are analyzed for different cases of governing parameters and compared to the results in some published studies.
COBISS.SI-ID: 15198998
3D numerical simulation of convective flow in porous media using an algorithm based on a combination of single domain and subdomain boundary element method is presented. The fluid flow in porous media is modeled with the modified macroscopic Navier-Stokes equations, coupled with the energy and species equations. The velocity-vorticity formulation is adopted, which results in decoupling the computational scheme into a kinematic and kinetic computational parts. Heat and mass flux through the cavity and flow fields are analyzed, focusing on the 3D nature of the phenomena.
COBISS.SI-ID: 14895894
A three-dimensional numerical study based on the boundary element method (BEM) was performed in order to study the problem of double-diffusive natural convection within a cubic enclosure filled with a fluid-saturated porous media, and subjected to horizontal temperature and concentration gradients. The fluid-flow within the porous media was modeled using space-averaged Navier-Stokes equations, coupled with energy and species equations. The used numerical algorithm is based on a combination of single domain and sub-domain BEM, and solves the velocity-vorticity formulation of the governing equations.The influences of the main controlling parameters, such as the porous Rayleigh number, Darcy number, Lewis number, and the buoyancy coefficient were investigated, by focusing on those situations, where the flow field becomes 3D. The results for overall heat and solute transfer through the porous enclosure are presented in terms of Nusselt and Sherwood numbers as functions of the governing parameters, and then compared to the numerical benchmarks published in literature.
COBISS.SI-ID: 15199510