Permodelan Numerik Aliran pada Pelimpah Bertangga Menggunakan Program OpenFOAM

Abstract

Diajukan The flow over steep slope spillways has high velocity and flow energy. It has potential to cause cavitation and scouring the riverbed. Stepped spillway is an alternative construction developed to minimize these dangers. Recently, experimental and numerical modeling by various geometric of steps have been developed. Numerical modeling has strength over experimental modeling in terms of time and research cost. OpenFOAM was chosen for this research because OpenFOAM is open source program that able to modeling multiphase case. The data required in this research was data of previous exsperimental research, such as geometri of spillway data, flow data, parameter hydraulic for validation. The aim of this research was to know numerical modeling performance, model sensitivity, and energy dissipation. The results indicated that numerical modeling using OpenFOAM have good performance. The range of RMSE In term of water level profile is 0,006-0,013, In term of flow velocity is 0,086-0,217, and in term of energy dissipation is 0,036-0,103. The size of mesh is the most influential parameter to the model result. The flow over stepped spillway of numerical modeling by discharge Q=0,179 m 3 /s or dc/h=1,50-Q=0,083 m 3 /s or dc/h=0,90 generates energy dissipation 51%-68%.