Empangan mempunyai pelbagai fungsi, dan ia bukan sahaja dibina untuk penjanaan kuasa elektrik, malah ia jugak untuk mengatasi masalah banjir. Walau bagaimanapun, air yang mengalir hendaklah dikawal supaya ia boleh mengurangkan kesan di kawasan hilir. Objektif utama kajian ini adalah untuk mengkaji profil permukaan, halaju dan tekanan dan untuk menetukan keupayaan blok penampan yg dicadangkan in model Empangan Tawau, Sabah. Model fizikal empangan Tawau telah dibina di makmal dengan skala 1:30 dengan menggunakan perspek, supaya ciri-ciri aliran dapat dilihat. Peralatan yang digunakan semasa menjalankan kajian ini ialah ‘Nixon Streamflow Meter Velocity’ dan Ultrasonic Flow Meter’. ‘Nixon Streamflow Meter Velocity’ digunakan untuk mengukur kadar aliran air model. Untuk menentukan ketepatan peralatan, ujian penentukaran seharusnya dilakukan bagi mengelakkan mengelirukan data. Melalui pemerhatian yang intensif, ciri-ciri aliran di lembah limpahan dan lembangan pegun telah ditentukan. Beberapa graf dan halaju, tekanan dan kedalaman air di dalam limpahan dan juga dalam lembangan telah dilplot. Kajian mendapati dua kes iaitu 50 L/s bersamaan dengan 246.5 m³/s dan 100 L/s bersamaan dengan 493.0 m³/s. Dari kajian ini, dapat disimpulkan ciri aliran bergantung pada jumlah pelepasan. Oleh itu, bagi reka bentuk blok penampan untuk lompatan hidraulik, aliran yang dijangkakan maksimum hendaklah ditentukan dan diperhatikannya ciri-ciri.
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The dam has a multi of functions, and it is not only built for power generation, but also a flood mitigation purposes. Flowing water should be controlled so that it can reduce the impact on the downstream area. The main objective of this study is to determine the velocity and to positioning of baffle blocks in stilling basin to reduce hydraulic jumps in Tawau Dam spillway model. The physical model of the Tawau Dam spillway was produced by scale 1:30 using perspex so that the characteristic of the flow could be visualized. The equipment used during this study are 'Nixon Streamflow Meter Velocity' and ‘Ultrasonic Flow Meter'. The 'Nixon Streamflow Meter Velocity' is used to measure the velocity of water at each point in the spillway and stilling basin while the 'Ultrasonic Flow Meter' is used to measure the flow rate of supply water to the model. To determine the accuracy of the equipment, the equipment had be ensure reliable set of calibration done data. Through an intensive observation, the flow characteristics in the spillway and stilling basin had been determined. Several graph had been plotted and velocity, pressure and water profile in the spillway as well as in the stilling basin. The study observed two cases of 50 L/s which is equalized to 246.5 m³/s and 100 L/s is 493.0 m³/s. From this study, it can be concluded that the characteristic of flows are depend on the amount of discharges. Therefore, to design baffle blocks for hydraulics jumps, the maximum expected flow should be determined and observed it characteristics.
A study of flow characteristics at stilling basin of tawau dam spillway, sabah_Siti Amirah Abu Hassan_A9_2019_MJMS