جستجوی مقالات مرتبط با کلیدواژه « direct numerical simulation (dns) » در نشریات گروه « مکانیک »

In this study, the turbulent kinetic energy redistribution process is investigated. To this aim, the direct numerical simulation (DNS) of incompressible flow of a Newtonian fluid through a channel at a shear Reynolds number of Reτ = 180 is used to produce a flow data base. Then, these data are statistically analyzed. The turbulent kinetic energy redistribution is studied using the pressure-strain-rate correlation tensor. Pressure and strain-rate fluctuations as well as the correlation coefficient between them are analyzed. An equation for the strain-rate fluctuations is derived whose terms are calculated based on the simulation results. Then, using a semi-analytical solution, the pressure-strain-rate correlation is computed and compared with the DNS results. The results of this research quantitatively show that the pressure strain-rate correlation transfers the kinetic energy that is produced in the stream wise component to the other two components.

In this research, numerical simulation of the interaction between a large bubble and a boundary layer, considering various parameters in a low Reynolds number flow, have been studied. This work can be a start for more complicated tasks with higher Reynolds numbers. The considered flow has been solved using the well-known front tracking method. The results indicate that the wall shear stresses considerably depend on the bubble location. Also,when bubbles are inside the boundary layer, the overall shear stresses and the skin friction drag increase.