Analisis Karakteristik Aliran Di Sekitar Pilar Jembatan Dengan Variasi Collar = Analysis of Flow Characteristics Around the Bridge Pillars with Collar Variations

Seri Tandira’pak. Analysis of Flow Characteristics Around Bridge Pillars with Collar Variations (supervised by Farouk Maricar and Bambang Bakri).
Flow characteristics in rivers can be influenced by the shape of the pillars. The presence of pillars in the middle of the river causes the width of the river to narrow and will have an influence on the behavior of the flow that passes through it. Changes in flow behavior represented in this flow velocity will also cause changes in the velocity distribution. The purpose of this research is to analyze the effect of pillars in reducing flow velocity with variations in vertical collar placement, analyze the relationship between flow velocity parameters to collar variations on bridge pillars, and analyze flow patterns around pillars. Based on the results of the research that has been carried out, it can be concluded that the flow velocity distribution shows significant changes in flow. The vertical direction flow velocity distribution without a collar on the pillar has a higher velocity than the flow velocity after the collar. This is due to the friction force on the collar and the bottom of the channel so that the flow becomes slower. The 3D collar has a greater influence on changes in velocity than the 2D and 2.5D collars. From the observations, it can be seen that the larger the collar used, the greater the velocity above the collar and the smaller the velocity below the collar. Changes in flow patterns can be seen with changes in flow direction, as well as changes in flow velocity values for each collar diameter variation and collar placement variation. By using the Root Mean Square Error equation, the value of the error rate between field measurements and simulation results is 6% in the state without collars, 15% in c3h0, 17% in c3h1 and 11% in the c3h2 state. Based on the RMSE value obtained, the simulation data is said to have a good level of truth.