|Source||CMES: Computer Modeling in Engineering & Sciences, Vol. 107, No. 4, pp. 297-320, 2015|
|Download||Full length paper in PDF format. Size = 1,974,826 bytes|
|Keywords||large eddy simulation; characteristic-based operator-splitting finite element method; backward-facing step flow; flow past a single cylinder; flow past two cylinders in tandem arrangement|
A numerical large eddy simulation (LES) method combined with the characteristic-based operator-splitting finite element method is proposed. The subgrid eddy viscosity model is used to calculate sub-grid stress in LES. In each time step, the governing equations are split into diffusive and convective parts. The convective part is first discretized by using the characteristic Galerkin method and then solved explicitly. The backward-facing step flow and the flow past a single cylinder are adopted to validate the model. Results agree with existing numerical results or experimental data. The flow past two cylinders in tandem arrangement is also studied at Re = 1000. The critical spacing is obtained in the range of 2.25D to 2.5D through the change characteristics of the streamlines and hydrodynamic forces as spacing. We further analyze the hydrodynamic forces at the critical spacing range.