Numerical Analysis of Energy Dissipation Ratio of Stepped Weirs Designed Using Reverse Stepped Thresholds

Abstract

Stepped weirs are a type of weir that has been designed for centuries to dissipate the flow energy on the chute channels. Many studies have been done on step geometry and are still being done to improve these weirs. In this study, the energy dissipation of the weir using reverse step thresholds has been examined with the Flow3D® software. A total of 18 analyzes were conducted using three models and six discharges. According to the results, the stepped weir designed using the reverse step thresholds could dissipate energy up to 18% more than the flat stepped weirs in the skimming flow regime. However, this value decreases as it passes towards the nappe flow regime.

Keywords

• Stepped spillway
• Flow3D
• Computational fluid dynamics (CFD)

Ters Basamaklı Eşikler Kullanılarak Tasarlanan Basamaklı Savakların Enerji Sönümleme Oranlarının Sayısal Olarak İncelenmesi

Öz

Basamaklı savaklar, şüt kanalı üzerindeki akım enerjisini sönümleyebilmek amacıyla tasarlanan ve yüzyıllardır kullanılan bir savak çeşididir. Bu savakların geliştirilebilmesi amacıyla basamak geometrisi üzerine birçok çalışma yapılmış ve yapılmaya devam etmektedir. Bu çalışma kapsamında, basamak uçlarına eklenen ters basamak geometrisindeki eşiklerin enerji sönümleme oranına etkisi Flow3D® yazılımı ile incelenmiştir. Üç farklı model ve altı farklı debi kullanılarak sürdürülen çalışmada toplam 18 adet analiz yürütülmüştür. Elde edilen sonuçlara göre, her bir basamak ucuna eklenen ters basamaklı eşiklerin, sıçramalı akım şartlarında, klasik basamaklı savaklardan %18’e kadar daha fazla enerji sönümleyebildiği, bu değerin nap akımı rejimine geçildikçe azaldığı gözlenmiştir.

Anahtar Kelimeler

• basamaklı savaklar
• Flow3D
• Hesaplamalı akışkanlar dinamiği (HAD)

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