Yazar "Aydogdu, Mahmut" seçeneğine göre listele

Listeleniyor 1 - 4 / 4
  • Küçük Resim Yok
    Öğe
    Comparison of oxygen transfer efficiency using new types of baffle blocks
    (Emerald Group Publishing Ltd, 2021) Aydogdu, Mahmut; Dursun, O. Faruk
    Oxygen is needed in water to maintain the natural ecological balance and the health of organisms. The amount of dissolved oxygen (DO) in water can be increased naturally in different ways. In particular, some hydraulic structures are designed so reoxygenation of water occurs spontaneously over a short distance and in a short time. Baffled chutes are designed to dissipate the energy of flow in irrigation systems, wastewater systems and stormwater systems. Staggered baffle blocks placed in a chute channel not only dissipate the energy of the water but also allow free oxygen transition between the water-air surface by means of hydraulic jumps. While water flows over, between and around the blocks, air bubbles are entrained into the water. The entrained air bubbles in the flow start to dissolve within the chute and the DO concentration in the water thus increases. In this study, the amount of DO was determined for baffle blocks with six different geometric shapes, different flow discharges and angle variations (10 & DEG; & LE; & alpha; & LE; 56 & DEG;). The oxygen transfer efficiency of the new baffle blocks designed in this study was found to be very effective. Different block types were found to have greater oxygen transfer efficiency for chutes with different slopes.
  • Küçük Resim Yok
    Öğe
    Estimation of Failure Rate in Water Distribution Network Using Fuzzy Clustering and LS-SVM Methods
    (Springer, 2015) Aydogdu, Mahmut; Firat, Mahmut
    In this study, a novel approach combining fuzzy clustering and Least Squares Support Vector machine (LS-SVM) methods is developed for estimation of failure rate in water distribution networks and for determination of the relationship between failure rate-effective factors. For this aim, failure data observed Malatya water distribution network during 2006-2012 was selected as study area. In first phase, estimation model was developed and tested for the complete data set in estimating the failure rate by LS-SVM method. Then, in order to develop a more sensitive estimation model and to improve the performance of LS-SVM, 9 sub-regions were defined with similar characteristics by using fuzzy clustering method. Then failure rate estimation was carried out for each of the sub-regions using by LS-SVM method. Feed Forward Neural Network (FFNN) and Generalized Regression Neural Network (GRNN) methods were also used for estimation of failure rate and the results were compared with those of LS-SVM. The criteria such as Correlation Coefficient (R), Efficieny (E) and Root Mean Square Error (RMSE) were used to evaluate the performance of models. The results showed that LS-SVM model gives better results in comparison with the FFNN and GRNN models. It was also determined that LSSVM model results for the sub-regions defined by clustering analysis are better and that the clustering analysis increases the estimation model performance in addition to the fact that the estimation results have become better. In conclusion, it can be possible to develop a more sensitive estimation models using fuzzy clustering and LSSVM methods.
  • Küçük Resim Yok
    Öğe
    Experimentally Verified Numerical Investigation of the Sill Hydraulics for Abruptly Expanding Stilling Basin
    (Springer Heidelberg, 2023) Aydogdu, Mahmut; Gul, Enes; Dursun, Omerul Faruk
    Energy dissipation structures, particularly stilling basins, are critical for defining the hydraulic jump characteristics that are suitable. Appropriate sill geometry for abruptly expanding stilling basins has been investigated and a central rectangular sill has been proposed in the literature. This study has examined the suggested central sill and alternative flip buckets for abruptly expanding stilling basins. A series of experimental and numerical studies were carried out for two different heights of the central sill and two different flip buckets. Simulations have been evaluated using experimental data of laboratory scale, which indicated that they were acceptably precise. For the simulations, the k-epsilon turbulence model RNG module was preferred using the volume of fluid methods. The PISO approach was chosen to resolve this equation system numerically. The results showed that the hydraulic jump characteristics are strongly influenced by sill geometry. For the Type-3 sill negative static pressures have not occurred and performs better at energy dissipation than other geometries examined in the study. Higher pressures occurred on the rectangular prism-shaped sills. Maximum static pressure happened on the Type-2 sill. The least static pressure was seen in the Type-4 sill type.
  • Küçük Resim Yok
    Öğe
    Farklı tasarımlara sahip venturilerin havalandırma performanslarının incelenmesi
    (2022) Turgut, Sinan; Dursun, O. Faruk; Aydogdu, Mahmut
    Akarsularda bulunan çözünmüş oksijen miktarı, hem suyun kalitesini gösteren hem de suda yaşayan canlıların ihtiyaç duyduğu önemli bir etkendir. Hidrolik yapıların akarsular ile temas etmeleri çözünmüş oksijen miktarına önemli oranda etki etmektedir. Kaskatlar ve venturiler suların havalandırılmasında kullanılan önemli hidrolik yapılardır. Venturi sistemlerinde daralan kesit içerisinde ilerleyen suyun hızının ani bir şekilde artması ile birlikte boğaz bölgesinde negatif basınçlar oluşur. Hız değişiminin neden olduğu bu düşük basınç havayı sistem içerisine sürükler. Sistem içerisine giren hava miktarı venturi girişi-boğaz kesitleri arasındaki orana bağlı olarak değişir. Bu çalışmada, farklı havalandırma delik sayılarına sahip 36, 42 ve 54 mm çaplarında dairesel venturilerin performansları deneysel olarak test edilmiştir. Boğaz bölgelerinin çapı, venturi çaplarının 0.5 ve 0.75 katı, boğaz bölgesi uzunluğu ise boğaz bölgesi çapına eşit ve 2 katı olarak seçilmiştir. Venturilerin üzerinde, boğaz bölgesinin orta noktasından başlayarak aralarındaki mesafe boğaz bölgesi uzunluğunun 0.75 katı olacak şekilde 6 mm çapında karşılıklı 3 çift delik açılmıştır. Venturilerin sistemle montajı sağlanıp sudaki Çözünmüş Oksijen Konsantrasyonu (ÇOK) üzerindeki etkileri incelenmiştir. Deneylerden elde edilen sonuçlar grafikler yardımıyla karşılaştırılarak yorumlanmıştır. Bu çalışmada, venturi çapları artarken ÇOK değerlerinin azaldığı gözlemlenmiştir. Ayrıca venturi boğaz bölgesi uzunluklarının artmasının da ÇOK değerlerini arttırdığı görülmüştür.