3-D Flow Structures Around and Fluid-Dynamic Forces Acting on a Rectangular Cylinder in Oscillatory Flow Available to Purchase

Three-dimensional flow structures around and fluiddynamic forces acting on a rectangular cylinder in oscillatory flow were investigated by numerical simulation using finite volume method. The computations were carried out for three kinds of cross-sections with width/height ratio (d/H) d/H = 0.6, 1.0 and 2.0 and for the amplitude of oscillating flow in the range of 2.5 ≤ the Keulegan-Carpenter number (KC) ≤ 25, the Stokes number (β) = 95. The calculated flow patterns and the drag and inertia force coefficients of Morison equation acting on the cylinder were compared with the experimental ones using a U-tube water tank. In this paper, we note how the KC number and the width/height ratio of the cylinders affect the unsteady and three-dimensional flow structures such as the “longitudinal vortices” and “transverse street” which formed in the case of a circular cylinder fixed in oscillatory flow, and how the C_D and the C_M values of Morison coefficients change corresponding to the change of the behavior of the flow patterns. Furthermore the relationship between spanwise correlation coefficient of the transverse force R(x₃), where x₃ is the spanwise position from the bottom of the cylinder, and three-dimensional vortex structures were investigated.