Three-dimensional study of parallel shear flow around an obstacle in water channel and air tunnel

Abstract

The purpose of this study is to show the effect of some physical parameters on a parallel shear flow. The variation of the velocity inlet and the influence of an obstacle placed at the bottom of a channel were analyzed. The governing equations based on K-e model in a line source downstream around a three-dimensional obstacle are determined by the finite volume method with SIMPLEC algorithm. The obtained results have allowed to establish the dynamic characteristics of this kind of flow. Horizontal and vertical velocity fields, Reynolds shear stress field, turbulence intensity and scalar concentration in the water channel and a wind tunnel were exposed. These results permit us to localize the maximum and minimum zones of turbulence, which help us to exploit those fields for different purposes such as energy extraction and port infrastructure.

Effect of heat transfer on shear flow around an obstacle

“…The K-e standard turbulence model leads to the best agreement between the numerical results of reference [20] and the experimental results of reference [18] for the water channel. This model will be adapted in all the rest of work.…”

“…The physical presentation of the proposed problem is shown in Figure 1. We have used the same geometry of [20]. The temperature above the obstacle is constant (T 1 = 15°C), while that around the obstacle is variable (T 2 = 15, 20, 25, and 35°C).…”

“…Figure 2 shows the variation of the horizontal velocity field in the water channel. The simulations were compared with experimental work [18] and numerical work [19,20]. A hybrid mesh of 336,793 nodes have been selected for the water channel; indeed, with these mesh numbers the error with respect to reference [18] does not exceed 1%.…”

“…The first part of this article is devoted to a presentation of the physical model and different equations that control the shear flow. The second part deals with the validation of numerical model for fixed inlet temperatures with the experimental results of reference [18] and the numerical results of references [19,20]. The third part focuses on the obtained results and the interpretations for the different inlet temperatures [21].…”

Heat transfer enhancement inside channel by using the Lattice Boltzmann Method

“…The results of other studies have provided evidence that, as the space between obstacles is decreased, the fluid flow in the channel is consequently enhanced, and that an increase in the Reynolds number (Re) enhances the process of heat removal around the obstacles, chiefly around the obstacle corners [2][3][4]. In a numerical study, Mohamed Toumi et al [5] investigated the three-dimensional shearing flows of Newtonian fluids around a cuboid obstacle. Their results showed that the locations after the obstacle and collision by the turbulent shearing flow generally formed a recirculation area with a high concentration scalar; this means the area at the boundary layer after the obstacle contained great turbulent energy.…”