Turbulent flow field characteristic research about riblet surface based on CFD technique

Numerical simulation about surface with a series of different size streamwise riblet structure has been carried out in turbulent flow by Computational Fluid Dynamics(CFD) technique. Reynolds stress equation model is adopted in the simulation process and full developed turbulent inlet boundary is set by program. Results are obtained from comparison between smooth and riblet surface. The streamwise vortex near riblet structure is an important reason of drag-reduction or drag-increase about riblet surface. The streamwise vortex changes flow field structure near wall and influences Reynolds stress in boundary layer near-wall region and wall shear stress. Then phenomenon of dragreduciton or drag increase appears on riblet surface.