Yazar "Cihan, Kubilay" seçeneğine göre listele
Listeleniyor 1 - 8 / 8
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Düşey Yüzlü Duvar Önünde Pervane Jetinin Neden Olduğu Oyulma(Kırıkkale Üniversitesi, 2022) Doğu, Ali; Cihan, Kubilay; Yuksel Ozan, Ayse; Yıldız, Osman; Ateş, HayriGemilerin seyir ve manevraları sırasında deniz tabanında meydana gelebilecek oyulmalar, önlem alınmadığı takdirde ciddi sorunlara neden olabilir. Oluşacak oyulmaların tahmini liman yapılarının stabilitesi için büyük önem taşımaktadır. Bu çalışmada, düşey yüzlü bir duvar önünde oluşan oyulma deneysel olarak incelenmiştir. Bu amaçla, 3.2x2.0x1.0 m ölçülere sahip deney tankının tabanına ortalama elek çapı d50= 0.24 mm ve özgül kütlesi ?=2650 kg/m3 olarak belirlenen kuvars kumu serilmiştir. Deneylerde 0.06 m çaplı pirinçten imal edilmiş bir pervane kullanılmıştır. Pervane kendi ekseni ile polikarbon esaslı düşey yüzlü bir duvar arasında 4 farklı konumda yerleştirilmiş ve 3 farklı dönüş hızında çalıştırılmıştır. Hız ölçümleri Akustik Doppler prensibi ile çalışan ADVP kullanılarak elde edilmiştir. Düşey yüzlü duvar ile pervane ekseni arasındaki mesafenin ve pervane dönüş hızının oyulma mekanizması üzerindeki etkilerine dair bulgular literatürdeki çalışmalarla karşılaştırılmıştır.Öğe Dynamic response of caisson type quay wall(Gazi Univ, Fac Engineering Architecture, 2022) Cihan, Hulya Karakus; Cihan, KubilayThe stability of caisson type quay wall considering the displacements were investigated for two different cases: in the first case, cyclic loading with different frequency was applied to the caisson type quay wall and the horizontal displacement (damage) on the structure was measured then by repairing the damage due to cyclic loadings after each experiment, experiments were performed with different cyclic loadings in similar way , ii: in the second case, same cyclic loadings used in first case were applied on structure successively and without repairing the damages on structure and the displacement (damage) on the structure was measured. After completion of the experiments for two different cases, the measured displacements were compared. Based on the experiment results, it was seen that for same cyclic motion, displacements of the second case were less than those in the first case. In addition, using experimental results for the first case, the instantaneous dynamic friction coefficient between concrete and the gravel base was calculated. It was found that ratio between calculated instantaneous dynamic friction coefficient and static friction coefficient oscillates around 1. Displacements, calculated by using double integration of the relative acceleration, were in compatible with the measured displacements during the experiments.Öğe Dynamic Responses of Block Type Quay Walls Under Cyclic Loading(China Ocean Press, 2021) Cihan, Hulya Karakus; Cihan, KubilayThe purpose of this research is to study the dynamic responses of gravity quay walls with block type consisting of three blocks experimentally. For this purpose, 1g shaking table tests were conducted under different cyclic loadings for two different saturated granular backfill materials (Soil 1 and Soil 2). In this study, D-n(50) of Soil 1 and Soil 2 are selected as 2.2 cm and 1.0 cm, respectively. During the experiments, accelerations, soil pressures and displacements were measured for each block. Test results pointed out that Soil 2 caused more damage on structures. The measurements for displacement and tilting of each block were discussed in view of acceptable level of damage in performance-based design given in PIANC (2001). The result of the study showed that the definitions of damaged levels given in PIANC (2001) were reliable for using in performance-based methods for seismic design of block type quay walls.Öğe Flow Characteristics in the Wake Region of a Finite-Length Vegetation Patch in a Partly Vegetated Channel(Mdpi, 2018) Yilmazer, Didem; Ozan, Ayse Yuksel; Cihan, KubilayAquatic vegetation in rivers and coastal regions controls the flow structure in terms of mean velocity and turbulence. The vegetation in the flow affects the transportation of nutrients, microbes, dissolved oxygen, sediment, and contaminants; therefore, the flow characteristics of different types of vegetation layers should be examined in order to understand the effects of vegetation on the flow structure. In this paper, the effect of the submergence ratio and SVF (Solid Volume of Fraction) of a vegetation patch, which was present across half of the channel in a spanwise direction, on the flow structure at the wake region was examined. For this purpose, different submergence ratios with different SVFs were considered in the experiments, and velocity measurements were performed in the wake region of the vegetation layer with an Acoustic Doppler Velocimeter (ADV). According to the results, the effect of different vegetation heights and SVFs on the velocity distribution was obtained. Moreover, inflectional velocity distribution over the cross-section in the wake region of the vegetation layer was obtained, and it was concluded that jet flow occurred in the non-vegetated half of the channel due to the vegetation layer.Öğe Keson yanaşma yapılarının dinamik davranışı(2022) Cihan, Hülya Karakuş; Cihan, KubilayKeson tip yanaşma yapılarının stabiliteleri (dayanımları) yer değiştirmeler göz önüne alınarak iki farklı durum için incelenmiştir: Birinci durumda, farklı frekanslara sahip döngüsel yükleme keson tip yanaşma yapısına uygulanmış ve yapı üzerindeki yatay deplasmanlar (hasar) ölçülmüştür sonrasında döngüsel yüklemesonucunda oluşan hasar görmüş kesit her deneyden sonra onarılarak deneyler benzer şekilde gerçekleştirilmiştir;ikinci durumda, birinci durum için kullanılan döngüsel yükleme yapıya peş peşe ve yapı onarılmadan uygulanmış ve yapı üzerindeki yer değiştirmeler ölçülmüştür. Her iki durum için yapılan deneyler tamamlandıktan sonra, ölçülen yer değiştirmeler karşılaştırılmıştır. Deney sonuçlarına göre aynı döngüsel yükleme için ikinci durumdaki yer değiştirmelerin birinci durumda ki yer değiştirmelerdendaha az olduğu görülmüştür. Ayrıca, birinci durum için beton ve anroşman arasındaki anlık dinamik sürtünme katsayısı deney sonuçları kullanılarak hesaplanmıştır.Anlık dinamik sürtünme katsayısı ile statik sürtünme katsayısı arasındaki oranın 1 değeri etrafında salındığı görülmüştür. Rölatif ivme değerlerinin iki kere integrasyonu ile hesaplanan yer değiştirmeler ve deneyler sırasında ölçülen yer değiştirmeler arasında iyi bir uyum bulunmaktadır.Öğe Reduction of propeller jet flow scour around a pile structure by using collar plate(Pergamon-Elsevier Science Ltd, 2021) Cihan, Kubilay; Hafızoğulları, Ayşe HazelIn this study, the effect of the collar plate usage on local scour around a pile due to propeller jet flow was investigated experimentally. Experiments were carried out for unconfined conditions, only existence of a pile and a pile with collar plate. Three different collar plate widths (W) and two different locations of the collar plate with respect to the seabed (hc) were used to determine the effect of the collar plate on scour. Three different rotational speeds were used and scour around a pile was measured by using an Acoustic Doppler Velocimeter Profiler (ADVP). Since the experiments were completed before reaching the equilibrium state, present study can be considered as a short-term study. The results of the experimental studies show that the amount of reduction of scour around a pile is sensitive to the collar plate width and location of the collar plate. A collar plate application is an effective way for reducing scour around a pile. The most effective type of collar plate was determined as a condition in which W/D and hc/y0 are equal to 3 and 0, respectively. The amount of reduction in scour around a pile was observed as 75%.Öğe Tam batmış bitki tarlasının açık kanal akım hızlarına etkisinin flow-3d ile modellenmesi(2022) Yilmazer, Didem; Ayna, Gökhan; Ozan, Ayse Yuksel; Cihan, KubilayBu çalışmada, deneysel olarak yapılan tam batmış bitkilerin açık kanal akımlarına olan etkisinin incelendiği bir çalışma, FLOW-3D ile modellenmiştir. Deney sonuçları ve sayısal model sonuçları karşılaştırılmıştır. Modellemede Yılmazer ve ark. [10] tarafından gerçekleştirilen deneye ait veriler kullanılmıştır.Öğe Unconfined propeller jet scour on clay/sand mixtures(Pergamon-Elsevier Science Ltd, 2022) Cihan, Kubilay; Dog, Ali; Yilmaz, Damla; Ozan, Ayse Yuksel; Yildiz, Osman; Sahin, CihanIn this study, scour due to an unconfined propeller water jet on homogeneous clay-sand mixtures was investigated experimentally. A total of 9 tests were conducted for the sand bed and 18 tests were carried out for the sand-clay mixture bed. Since clay contents (p) of 0, 5 and 10% by weight were used in the experiments, scour in poorly cohesive sand-clay mixture bed was taken into account. Propeller diameters (Dp) were 0.06 and 0.09 m. Dimensionless propeller heights (y0/Dp) were defined as 1.67, 1.11, 1.0. The increase in clay content causes a decrease in the scour depth and changes the formation of scour profiles. The parameters y0/Dp, F0 (densimetric Froude number), p were found to have significant effects on the behavior of clay-sand mixtures. Considering the test results, equations were proposed to estimate the maximum depth and length of the scour hole formed in the equilibrium condition. In addition, by modifying the equation proposed by Hong et al. (2013), a new equation is proposed for the estimation of temporal maximum scour depth due to the propeller water jet on the sand and weakly cohesive sand-clay mixture beds.
