Direct Numerical Simulation of An Axially Rotating Pipe Flow : (2nd Report, Turbulent Heat Transfer for Low Rotation Rate)

Abstract

A direct numerical simulation (DNS) with turbulent transport of a scalar quantity was performed for fully-developed turbulent rotating pipe flows. In this paper, the Reynolds number, which is based on bulk velocity and pipe diameter, was constant ; Re_b=5293, and the rotation ratio of a wall velocity to a bulk velocity were set to be 0.25, 0.3 and 0.35. A uniform heat-flux was applied to the wall as a thermal boundary condition. Prandtl number of the working fluid was 0.71. The turbulent statistics such as the mean temperature, temperature fluctuations, and scalar flux distribution were obtained. The turbulent heat transfer decreases with the rotating ratio increase. Moreover, the scalar-flux budgets were also obtained for each rotation ratio.