The problem of unsteady compressible fluid flow in an enclosure induced by thermoacoustic waves is studied numerically. Full compressible set of Navier-Stokes equations are considered and numerically solved by boundary-domain integral equations approach coupled with wavelet compression and domain decomposition to achieve numerical efficiency. The thermal energy equation is written in its most general form including the Rayleigh and reversible expansion rate terms. Both, the classical Fourier heat flux model and wave heat conduction model are investigated.
COBISS.SI-ID: 13062934
We developed a fast algorithm based on the fast multipole method for simulation of heat transfer and incompressible fluid flow. We achieved a significant reduction of CPU time and computer storage requirements. The algorithm was used to simulate natural convection.
COBISS.SI-ID: 13066774
This paper deals with the efficient 3D multidomain boundary element method for solving a Poisson equation using linear mixed boundary elements. Interface boundary conditions between subdomains lead to an overdetermined system matrix, which is solved using a fast iterative linear least square solver. The accuracy, efficiency and robustness of the developed numerical algorithm are presented in comparison with the competitive BEM. The efficiency is demonstrated using a mesh with over 200,000 hexahedral volume elements on a personal computer with 1 GB memory.
COBISS.SI-ID: 13063958
The classical Navier-Stokes system of equations, which forms the basis for derivation of modern flow simulation tools, was modified, to incorporate additional micro effects into the computational method. The submitted work presents results of flow, thermal and micrortation fields solved with a computational algorithm, based on the application of the Boundary Element Method to the modified N-S equations. Results showed that considering micro rotation of particles does influence momentum transfer in the fluid and consequently impacts the convective heat transfer mechanism.
COBISS.SI-ID: 13040150
This paper deals with the influence of biodiesel on some tribology characteristics of a bus diesel engine. Attention was focused on the biodiesel influence on the pump plunger surface roughness, on the carbon deposits in the combustion chamber, on the injector and in the injector nozzle hole. The obtained results indicate that biodiesel usage may even improve the pump plunger lubrication condition. It was found out that the variation of the nozzle discharge coefficient has to be taken into account only if high accuracy of numerical simulation is desired.
COBISS.SI-ID: 13020950