Three-dimensional numerical analysis of turbulent structure in a straight channel flow with a sand ridge by using Reynolds stress model

A numerical analysis has been performed for developing turbulent flow in a straight channel with a sand ridge by using a Reynolds stress model. Governing equations are transformed from the physical plane to the calculation plane by boundary-fitted coordinate systems. The calculated results are compared with the experimental data available. As a result of this examination, it made clear that the present method was able to predict cellular secondary currents which are induced by anisotropy of turbulence and the experimental results of Reynolds stresses without a great discrepancy. Considering the behaviour of the secondary flow, it may be said that the first sand ridge is generated by the secondary flow of the corner region.