Numerical simulation of low-Reynolds number flows past rectangular cylinders based on adaptive finite element and finite volume methods

Abstract

The flow past rectangular cylinders has been investigated by two different numerical techniques, an adaptive finite-element (AFEM) and a finite-volume method (FVM). A square and a rectangular cylinder with width-to-height equal to 5 are taken into account. 2D computations have been performed for different Reynolds numbers in order to consider different flow regimes, i.e. the stationary, the periodic and the turbulent flow. The comparison between the two methods regarded both the reliability of the computed solutions and the overall resulting efficiency of the methods. Velocity profiles and integral parameters such as Strouhal number, drag coefficient and recirculation length have been compared. A good agreement between the adaptive FEM and the FVM computations, as well as with the available literature results, has been found. The computational effort has been evaluated in terms of used degrees of freedom in space and time and human resources employed to reach the mesh and timestep-length independence of the solutions. Relevant outcomes of this work are the cross validation of an adaptive FE method and a popular open source FV code.