On Turbulent Flow with Streamwise Rotation

The flow in rotating passages attracts great interests in the field of turbomachines. The flow in such devices is subjected to Coriolis and centriffigal forces resulted from general rotating vector. Since much efforts have done in the classical spanwise rotating channels, this study has investigated the turbulent channel flow with system rotation in the streamwise direction, in which the main rotating vector coincides with the flow direction, aiming at generalizing the system of rotation. Direct numerical simulation has been perfonned using spectral methods for a wide range of rotation number $\mathrm{R}\mathrm{o}_{\tau} $ up to 15 and a Reynolds number of 150. Low rotation number shows slight effect in turbulence characteristics of that of plane channel without system rotation. No laminarization features have been captured even in high numbers that differs from the classical spanwise rotation case. Both walls attain the same level of turbulence intensities. The simulation shows nearly symmetric profiles for the mean streamwise velocity around the centre of the channel. More augmentation in the core region has been observed at increasing the rotating rate. The study concludes some distinct characteristics and also some common features with the classical spanwise rotation case