Önder KOÇYİĞİT

7944

Liman tabanında gel-git sonucu oluşan değişimin fiziksel ve sayısal modellemesi

Bu çalışmada laboratuvar ortamında bir liman modeli tabanında, gel-git sonucu oluşan sediment hareketlerinin fiziksel ve sayısal model sonuçları irdelenmiştir. Araştırmada gel-git sayısı, liman giriş ağzının yeri ve büyüklüğünün tabandaki sediment hareketine etkisi incelenmiştir. Çalışmada sedimenti temsil etmesi için "Katyon Reçinesi" isimli çok hafif bir malzeme kullanılmıştır. Bu malzeme sayesinde fiziksel model içinde laboratuvar şartlarında oluşan düşük akım hızlarına karşın büyük aşınma ve depolama bölgelerinin oluşumu sağlanmıştır. Hidrodinamik ve su kalitesi karakteristiklerinin ve sediment taşınımının sayısal modellemesinde iki boyutlu derinlik boyunca integre edilmiş (DIVAST) bir sayısal model ile "quad-tree" olarak adlandırılan düzgün yapılı olmayan ağ üretme tekniği birleştirilerek kullanılmıştır. Sonrasında modele taban seviyesinin değişimi tahmini de eklenmiştir. Laboratuvardan ve sayısal modelden elde edilen hidrodinamik ve taban seviyesi sonuçları karşılaştırılmış ve sayısal model tahminleri ile laboratuvar ölçüm sonuçlarının yakın olduğu gözlenmiştir. Ayrıca "Katyon Reçinesi" nin laboratuvar şartlarında sediment taşınımı sürecinin fiziksel modellemesinde çok uygun bir malzeme olduğu sonucuna varılmıştır.

Physical and numerical modelling of bed level changes of a harbour due to tidal motion

Details are given of a combined physical and numerical model study of the sediment transport processes in a square harbour caused by tidal motion. Effects on bed level changes due to tidal currents and the configuration of the harbour entrance were investigated. A light weight material called Cation Resin was used in this study to represent bed sediment in the laboratory experiments. This material enabled the erosion and deposition processes to be exaggerated within the model harbour, in which the magnitude of the flow velocities was relatively small. An unstructured mesh generation technique, namely a quad-tree grid, was incorporated into an existing two-dimensional depth-integrated numerical model (DIVAST) to predict the hydrodynamic characteristics and the transport of water quality constituents and the sediment particle fluxes. The numerical model was further refined to include the prediction of bed level changes. Detailed comparisons between the numerical model predictions and the laboratory data were undertaken. It was found that the numerical model predictions and the laboratory measurements were in good agreement. It was also concluded that Cation Resin was an appropriate material to be used for physical modelling of sediment transport processes in laboratory model studies.
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Teknik Dergi-Cover
  • ISSN: 1300-3453
  • Yayın Aralığı: 6
  • Yayıncı: TMMOB İnşaat Mühendisleri Odası
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Önder KOÇYİĞİT