Master Degree / Yüksek Lisans Tezleri

Permanent URI for this collectionhttps://hdl.handle.net/11147/3008

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  • Master Thesis
    Experimental and Numerical Investigation of Piping in Uniform Embankment Dam With Weak Layer at the Upper Region
    (Izmir Institute of Technology, 2022) Okan, Merve; Tayfur, Gökmen; Bor Türkben, Aslı
    From the past to nowadays, earth-fill dams have been built thanks to their advantages, however, piping is a problem that earth-fill dams can experience and then fail. While there are many studies about the overtopping failures of the dams, there are not too many surveys about dam failures due to piping. Dams having a height of 0.6 m, a bottom width of 2 m, and a crest width of 0.20 m were built in a channel of 1 m wide, 0.81 m high and 6.14 m long. 3 different scenarios have been created and the evolution of dam failure resulting from seepage at the dam was recorded by six cameras located at different locations. In the closed system, water was pumped from the lower reservoir to the upper channel. The dam was constructed by using a mixture consisting of 85 % sand and 15 % clay. A circular tunnel with a diameter of 2 cm was created at the middle or corner of the dam according to the scenario and at 6 cm below the dam crest. The breach areas at different time instants at upstream and downstream sides are determined by using the Gauss Area calculation method and by image processing, and then it has been found that methods give close values to each other. Breach discharge and time-varied velocity values were determined by using the continuity equation. Empirical relations were intended to be derived for the breach flow rate and empirical relations represented in the literature were trialed by using experimental findings.
  • Master Thesis
    Computation of the Convection Diffusion Equation by the Fourth Order Compact Finite Difference Method
    (Izmir Institute of Technology, 2015) Bajellan, Asan Ali Akbar Fatah; Tayfur, Gökmen
    This dissertation aims to develop various numerical techniques for solving the one dimensional convection–diffusion equation with constant coefficient. These techniques are based on the explicit finite difference approximations using second, third and fourth-order compact difference schemes in space and a first-order explicit scheme in time. The suggested scheme has been seen to be very accurate and a relatively flexible solution approach in solving the contaminant transport equation for Pe ≤ 5. For the solution, the combined technique has been used instead of conventional solution techniques. The accuracy and validity of the numerical model are verified. The computed results showed that the use of the current method in the simulation is very applicable for the solution of the convection-diffusion equation. The technique is seen to be alternative to existing techniques. This dissertation is divided into six chapters: The derivation of the convective diffusion equation is given in Chapter 2. The main idea behind the higher order finite difference technique is given in Chapter 3. The numerical approximations to CDE described with ten different explicit schemes are introduced in Chapter 4. The results of numerical experiments using second, third and fourth-order compact difference schemes are presented in Chapter 5. Chapter 6 is devoted to a brief conclusion. Finally the references are introduced at the end.