Direct numerical simulation of a puff and a slug in transitional cylindrical pipe flow

摘要

A numerical simulation of a puff and a slug structure in a transitional pipe flow at a Reynolds number of Re = 2200 and Re = 5000 was conducted. The simulation was carried out with a spectral element method combining a high accuracy with an adequate resolution in the different regions of the pipe. The velocity field within the puff was also examined. In a coordinate system traveling with the mean velocity, recirculation regions were found both near the trailing and leading edges which agrees at least qualitatively with experimental data. Streamwise vortices were also observed predominantly in the trailing-edge region.