To well understand the mechanism of energy dissipation in a turbine flow passage and explore the change of turbulence structures, a spatio-temporal sinusoidal oscillatory mode is numerically tested in a turbulent curved-channel flow using large eddy simulation (LES). Six computing cases incorporated with different vibrating parameters of the wall are dealt with, and the distributions of the pressure, vortices, and other turbulent statistical quantities in the near wall regions are studied. The results show that the turbulence intensities increase largely in near wall regions, suggesting that the viscous sublayer is thinner as a result of the velocity graduate's rise due to the spanwise wall oscillation. Furthermore, the energy dissipation is increasing. The present study also shows that the mechanism of energy dissipation by spanwise-wall oscillation is strongly related to the spanwise-vortex generated at the edge of the viscous sublayer by the periodic Couette flow layer.
|Number of pages||6|
|Journal||Advances in Water Science|
|Publication status||Published - Sep 2008|