Low-Reynolds-number effects derived from direct numerical simulations of turbulent pipe fow

Abstract

Fully developed, statistically steady and non-swirling turbulent flow through straight pipes of circular cross-section is investigated by means of direct numerical simulation. A finite-volume scheme of second-order accuracy and a semi-implicit time integration scheme of the same order of accuracy are used to integrate the incompressible Navier-Stokes equations on staggered grids. Significant low-Reynolds-number effects are observed in the mean axial velocity, the components of the Reynolds stress tensor, the pressure and vorticity fluctuations, the turbulent kinetic energy budget and two-point velocity correlations. It is confirmed that turbulence data obtained in the near-wall region do not scale on wall variables. Within the range of Reynolds numbers investigated, the non-dimensional streak spacing increases slightly with Re_tau