Numerical study of Laminar flow past one and two circular cylinders

Abstract In the present paper, a finite element program was developed in order to simulate the vortex shedding behind one or two circular cylinders. The velocity-pressure formulation was used to solve the unsteady, two-dimensional, incompressible Navier-Stokes equations. The characteristics of the time integration schemes (implicit-Euler and Crank-Nicolson) were studied. Using the Crank-Nicolson scheme, the classical von Karman vortex street was found in the solution of the Navier-Stokes equations. The drag lift coefficients as well as the Strouhal number calculated from our numerical data for Re ⩽ 500 were compared both with experimental and numerical results and good agreement was observed. The critical Reynolds number Re c found in the present study was well within the range of experimental measurements. Flow past two circular cylinders arranged behind one another at different intervals was also studied for Re = 100 . The pressure distributions around the upstream and downstream cylinders together with their vortex shedding frequencies as a function of cylinder interval were determined and compared with the experimental values. Discontinuity changes in the flow pattern, the Strouhal number and the pressure distribution were detected.