Characteristics of unsteady flow around two successive rectangular ribs on floor of a wind tunnel

The presence of two or more mounted ribs in air duct or wind tunnel causes strong turbulence, affecting basic flow properties in mechanical or agricultural applications. The purpose of this work was the detailed analysis and visualization of turbulent flow around two successive ribs on the floor of a wind tunnel, with dynamic approximation. The statistical numerical results of flow parameters of the present numerical experiment were quantitatively compared with respective wind tunnel experimental data, in order to check the validity of the proposed mathematical model. Instantaneous values of both velocity components obtained from the direct solution of Navier-Stokes equations and the wind tunnel experiment were used to calculate the statistical data of turbulent flow, such as time-averaged stream and cross-wise velocities, turbulent intensities and turbulent kinetic energy. The validation of proposed model was confirmed by the satisfactory agreement between the numerical experiment and laboratory experiment with respect to turbulence statistics, such as averaged velocities, turbulence intensities and turbulent kinetic energy. The instantaneous streamlines around two successive rectangular ribs was presented for the first time, demonstrating the chaotic behavior of the flow. Intense variations of velocity components, were developing between the ribs and specifically at the beginning of the first roof to the second roof of ribs. The turbulence statistics showed that the maximum values of turbulent parameters were observed mainly over the two successive ribs. The direct simulation model overestimated the maximum values of turbulent parameters comparing to the corresponding experimental values.