The Influence of Stilling Basin Length on Velocity Changes Using Computational Fluid Dynamics Analysis

Abstract

There are many ways to model hydraulic structures. Making prototype of hydraulic structures are costly, so alternative methods need to make an efficient model. Computational Fluid Dynamics is reliable to perform the variations model of hydraulic structures, which means enabling to create of many simulations without dangering people and safely at the cost. This paper discussed the influence of the stilling basin length variation on velocity changes. The stilling basin model draws on a 3-dimensional computer-aided design with three differences in length and export files as .stl. The analysis of Computational Fluid Dynamics is using Simflow open-source CFD software. The simulation is performed at a constant Flow Rate of 65 m3/s. There are three points of velocity monitoring, namely P1, P2, and P3. The position of P1 is located at the center of the stilling basin. P2 and P3 are located at the bottom and the top of the End Sill. The final stage of simulation showed that the stilling basin with the 10 meters length has a velocity at P1, P2, and P3 of 9.43, 7.16, and 5.25 m/s. Other velocity results for 9.5 meters length (P1, P2, P3) are approximately 9.55, 7.92, and 5.78 m/s. The last case using 9 meters length has results of 9.61, 8.30, and 5.83 m/s of velocity. The conclusions of the results showed that shortening the stilling basin length is affecting an increase in the velocity.