Turbulent flow simulation using large eddy simulation combined with characteristic-based split scheme

• A numerical method of large eddy simulation combined with a characteristic-based split scheme.
• The CBS discretes the momentum equation in space domain by split algorithm.
• Turbulent flow simulations in a lid-driven cubical cavity and two 90° pipes.
• An additional pair of vortexes has been observed which is not reported before.

A numerical method of large eddy simulation (LES) combined with a characteristic-based split scheme (CBS) is proposed. The CBS scheme is introduced to discretize the motion equation in the time domain along the characteristic line, and the space domain is discretized by the split algorithm, which calculates the velocity and pressure separately. Turbulent flow simulations in a lid-driven cubical cavity and two circular section 90° pipes are conducted, and the results are validated by comparison with experimental data and other direct numerical simulation results. For a circular section 90° pipe, an additional pair of vortexes that is near the curved section inner side has been observed, and their rotational direction is the same as that of the main vortex. To the author’s knowledge, this type of four-vortex structure has not been previously reported.