application of backward probability method in pollutant source tracking in non-uniform flow riversalireza ghanem.sc. student of water structures, tarbiat modares university, tehranmehdi mazaheri assistant prof., department of water structures, tarbiat modares university, tehranjamal mohammad vali samaniprofessor, department of water structures, tarbiat modares university, tehranintroductionriv...

A non-oscillatory numerical scheme based on a general solution of unsteady advection–di usion equations is presented. A general solution for initial value problems of linear two-dimensional unsteady advection–di usion equations is obtained using the spectral method. The resulting numerical scheme is explicit with respect to time, and ful lls the Patankar’s positive coe cients condition for any ...

A hardware-based approach for visualizing unsteady flow fields by means of Lagrangian-Eulerian advection is presented. Both noise-based and dyebased texture advection is supported. The implementation allows the advection of each texture to be performed completely on the graphics hardware in a single-pass rendering. We discuss experiences with the interactive visualization of unsteady flow field...

Tracer-particles, massless particles that are advected throughout the flow domain, are an important factor in computational solutions. The utility of tracer-particles, which sample and report relevant solution data, is predicated upon an accurate advection algorithm. The objective of this research was to investigate the ability of existing techniques, physical-space and logical-space advection,...

A hardware-based approach for visualizing unsteady flow fields by means of Lagrangian-Eulerian advection is presented. The implementation allows texture advection to be performed completely on the graphics hardware in a single-pass rendering. We discuss experiences with the interactive visualization of unsteady flow fields that become possible due to the high visualization speed of the hardware...

It is known that the standard Galerkin finite element method (SGFEM) based on low order piecewise polynomials is unsuitable for the solution of steady and unsteady advection diffusion problems. In case the advection term dominates the diffusion one or small time steps are employed, numerical solutions obtained by SGFEM suffer from nonphysical oscillations, unless appropriately designed meshes a...

In the present study, analytical solutions are developed for three-dimensional advection-dispersion equation (ADE) in semi-infinite adsorbing saturated homogeneous porous medium with time dependent dispersion coefficient. It means porosity of the medium is filled with single fluid(water). Dispersion coefficient is considered proportional to seepage velocity while adsorption coefficient inversel...