DOI: 10.1615/ICHMT.2009.TurbulHeatMassTransf
ISBN Print: 978-1-56700-262-1
ISSN: 2377-2816
Direct numerical simulation for transient turbulent pipe flow with sudden wall-rotation
SINOPSIS
Transient phenomena in turbulent pipe flow with sudden wall-rotation were investigated by means of the direct numerical simulation (DNS). Due to the sudden rotation, the wall friction becomes small and the bulk velocity increases. There are differences of the time-development of the mean quantity profiles between the weak and strong rotation cases. In the case of the weak rotation, the change of the mean quantity is small. In the strong rotation case, the large-scale motion is attenuated and the flow laminarization occurs under the stable state after the start of rotation. The duration of the stable state does not become longer in the very strong wall-rotation. Since the sudden rotation causes the unsteady inertial force, the turbulent structures are arranged spirally. Furthermore, during the wall friction increases, the wide low-speed structures appear.