Application of Computational Fluid Dynamics Model to Study the Scale Effects in Hydraulic Laboratory Experiments

Hydraulic scale models are widely used to investigate design and operation issues in hydraulic engineering. In these model studies geometric, kinematic and dynamic similarities should be followed strictly. In reality, however, it is difficult to follow all similarity laws. In many cases, some aspects of similitude may be neglected, and only those most important factors can be preserved. This will inevitably lead to some difference between the prototype and scale model results, which is called model scale effects. In this paper, computational fluid dynamics (CFD) modeling is used to study the hydraulic model scale effects. The discharge capacity of flow passing through an ogee spillway and flow fields in pump intake are used as two case studies. These case studies illustrate the significance of using similarity laws in the hydraulic scale model, and illustrate the feasibility of using CFD model to indirectly investigate hydraulic model scale effects.