A numerical-experimental study of confined flow around rectangular cylinders

Abstract

A previous numerical study by Davis and Moore of vortex shedding from rectangles in infinite domains is extended to include the effects of confining walls. The major changes to the numerical modeling are the addition of a direct solver for the pressure equation and the use of an infinite-to-finite mapping downstream of the rectangle. The parameters in the problem are now Reynolds number, rectangle aspect ratio, blockage ratio, and upstream velocity profile. As each of these is varied, the effects upon the forces acting on the rectangle and the structure of the wake are discussed. Streakline plots composed of multishaped passive marker particles provide a clear visualization of the vortices. These plots are compared with smoke-wire photographs taken from a wind tunnel test. Strouhal numbers obtained both computationally and experimentally are compared for two values of the blockage ratio. Moving recirculation zones which appear between the wake and the walls are discussed.

Numerical Simulation of Flow around Diamond-Shaped Obstacles at Low to Moderate Reynolds Numbers

“…The behavior of this non-dimensional number based on the previous statements is in good agreement with the results of previous investigations. Although there is a lack of similar 2-D laminar studies in the case of flow around diamond-shaped obstacles, but it can be noticed that there would be a rise of Strouhal number with an increase in the blockage ratio as presented in the literature, [1,5]. Also, a local maximum in the St has been reported by various works in the case of flow around rectangular cylinders.…”

“…A smaller value of critical Reynolds number Re ≈ 54 was determined by Klekar and Patankar [4] based on a stability analysis of the flow. Davis et al [5] interpreted flow around a rectangular cylinder for a wide range of Reynolds numbers and aspect ratios of 1/4 and 1/6. Two-dimensional study of this problem for Reynolds numbers of 90 to 1200 and aspect ratios of 1/8 and 1/4 has been done by Mukhopadhyay et al [6].…”

A Turbulent Flow without Particle Mixing

“…In contrast to the inviscid scheme utilized in the previous simulation, a finite difference method (Davis and Moore, [1982]; Davis et al, [1984]) was employed here to study the motions of the particles for various Stokes numbers at a flow Reynolds number of 100. The results are shown in Figure 3 for St = 0.01, 1.0, and 10.0.…”

Numerical analysis of confined flow past permeable square cylinder with CE/SE method

“…The computational domain covers grid point of 602 × 162, and the space and time interval are 0.1 and 0.005, respectively. The initial and boundary conditions were referred in the literature (Davis and Moore, 1984;Li and Humphrey, 1995). The no-slip boundary conditions were set at the impermeable cylinder surface.…”