Pressure distribution around a near-wall circular cylinder subjected to steady current


Ocean Engineering and Technology Research Center, Iranian National Institute for Oceanography and Atmospheric Sciences


Flow around a circular cylinder near plane wall has been simulated using Open source CFD codes of OpenFOAM in different flow regimes (Re=100, 200, 3900) and different gap ratios (G/D= ∞, 1, 0.5, 0.2). Time-averaged pressure coefficients around a circular cylinder computed and compared with each others in different cases. Other features of flow including drag and lift coefficients, Strouhal number, separation angle and stagnation angle are also computed to describe the state of flow better. It has been shown that pressure distribution around the circular cylinder can be utilized to describe the variations in hydrodynamic force coefficients as well as other features of wake flow such as separation and vortex shedding phenomenon near a plane boundary. Plane wall effects on pressure distribution in different flow regimes investigated and it was found that the inception of vortex shedding suppression can be deduced from pressure distribution pattern, through pressure gradient between free-stream-side and wall-side of cylinder. In addition, a rapid increase in the maximum value of positive pressure coefficient can be concluded.

[1] Zdravkovich, M. M., Flow Around Circular Cylinders, Vol 1: Fundamentals. Oxford University Press Inc, 1997. [2] Thorn, A., "The flow past circular cylinders at low speeds". Proceedings Royal Society, A141, 651-69, 1933J. [3] Homann, F., "Influence of higher viscosity on flow around cylinder" (in German). Forschung aus dem Gebiete des Ingenieiuwesen, 17, 1-10, transl, 1952. NACA TM 1334., 1936J. [4] Williamson, C. H. K., and Roshko, A. (1990J). Measurements of base pressure in the wake of a cylinder at low Reynolds numbers. Zeitschriit fur Flugwissenscbeiten und Weltraumorsdwng, 14,38-46. (Exp. 50