Numerical Modeling of Sharp-Crested Triangular Plan Form Weirs Using FLUENT

Weirs are hydraulic structures used for measuring flow rate. Triangular labyrinth weir is a kind of non-linear weirs which are used to control free flow passing over weirs in low width. Accordingly, the present paper attempted to investigate the characteristics of flow in triangular labyrinth weirs through FLUENT Software. In this regard, using GAMBIT Model, geometrical and grid generation conditions of flow was created for flow field solution. Using numerical model of Fluent, boundary conditions and flow field conditions were implemented for the model. Meshing conditions is for about 300 thousands cells with at most about 11% error. In the next test, simulation error is decreased about 30% through minimizing the size of computational cells and flow field solution for 580 meshes and the maximum depth simulation error reaches to 8%. Re-decreasing the cells’ size and the limited number of about 1 million computational cells causes that simulation error approaches to 7%.Through more careful computational cells selection and given to hardware limitations during simulation time, about 580 thousands cells with average size of 20 mm were selected. It is due to the fact that smaller selection leads to the increase of flow field modeling time up to 2 times more than time. Numerical model of FLUENT is highly able to simulate flow field in labyrinth weirs.