Numerical study of low-Reynolds-number flow past two tandem square cylinders with varying incident angles of the downstream one using a CIP-based model. (15th July 2016)

• Record Type: Journal Article
• Authors: Zhao, Xizeng; Cheng, Du; Zhang, Dake; Hu, Zijun
• Is Part Of: Ocean engineering. Volume 121(2016)
• Page Start: 414
• Page End: 421
• Publication Date: 2016-07-15
• Subjects: Flow past cylinder -- Tandem square cylinders -- CIP method -- Shear flow -- Immersed boundary method -- Vortex shedding; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2016.06.005
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: Two-dimensional flow past two tandem square cylinders with varying incident angles of the downstream one is numerically investigated using an in-house code named the CIP-ZJU model (a Constrained Interpolation Profile based-model in Zhejiang University). The model is built on a Cartesian grid system governed by the Navier–Stokes equations using the CIP method for flow solver, and employs an immersed boundary method for the treatment of fluid-structure interactions. Reynolds number in the computation is just set to a constant value of Re =100. In the initial stage of numerical simulation, a shear flow condition is applied to reduce the initial convergence time. The position and incident angle of the upstream cylinder is fixed while incident angle of the downstream one varying from 0° to 45°. The spacing ratio ( L / D, L is the streamwise center to center space between two cylinders and D is the square side length) of two cylinders is set at different values of 2, 3, 4, 5, 6 and 7. It is found that there exist two kinds of flow modes with different spacing ratios and incident angles. Particularly at L / D =4, there is a saltation phenomenon of the flow mode when the angle changes from 20° to 25°, which has not been studied before. Highlights: Flow past two tandem square cylinders is studied using CIP method. A shear flow condition is used in the initial phase. The center-to-center distance and incident angle of downstream cylinder is studied. The results show some interesting phenomenon which are not found previously.