Numerical investigation for homogeneous turbulent flow with uniform shear under streamwise rotation

Abstract

In this study, the direct numerical simulation (DNS) for homogeneous shear turbulence in the system rotating along the streamwise direction is fulfilled. Due to the rotation effect, the turbulence energy becomes small during the initial short time and the Reynolds shear stress are suppressed more strongly with increasing the system angular velocity. Since the redistribution related to the rotation and pressure-strain terms of the Reynolds normal stress is weakened by the streamwise rotation, the anisotropy of the normal stresses is strengthened. In the strong rotation case the anisotropy of the velocity spectra is strong in the whole wavenumber region in contrast with the isotropy of the non-rotating case in the large one. From the viewpoints of the probability density function (PDF) for the vorticity vector angle and visualization for the vortex structure, we find that the vortex structures become large and stand in a line by the streamwise rotation axis. Moreover, we suggest that the rapid distortion theory (RDT) simulation reproduces the rotation effect on the mean quantities of the DNS results in only short time immediately after a calculation start.

Keywords

• turbulence
• uniform shear
• streamwise system rotation
• direct numerical simulation
• rapid-distortion theory