Sharif Digital Repository

Turbulent Schmidt number as an important parameter in computational fluid dynamic (CFD) simulations is strongly dependent on height, whereas it is mostly considered to be constant in the literature. This paper presents a new variable turbulent Schmidt number formulation which can calculate the relative concentrations (RCs) in neutral atmospheric conditions more accurately. To achieve this aim, RCs from continuous releases are calculated in different distances by the analytical Gaussian plume mode. CFD simulations are carried out for single stack dispersion on a flat terrain surface and an inverse procedure is then applied so that different turbulent Schmidt numbers are used as inputs to... 

This paper deals with numerical modeling of water flow which is generated by the break of a dam. The problem is solved by applying a new Incompressible Smoothed Particle Hydrodynamics (ISPH) algorithm based on projection method. The proposed ISPH model has two steps. In the first step, the incompressibility of fluid is maintained regarding to the changes of intermediate and initial particles densities at the first half-time step (stability step). In the second step, by computing the divergence of the intermediate secondary velocity at the second half-time step (accuracy step), the incompressibility is satisfied completely. In fact, by using this method both stability and accuracy are...