Ender Demirel

Hydrodynamic Modeling of Dam-Reservoir Response during Earthquakes

A computational model is developed to analyze the hydrodynamic behavior of dam reservoirs during earthquakes. The math- ematical model is based on the solution of two-dimensional (2D) Navier-Stokes equations in a vertical, semi-infinite domain truncated by a far-end boundary condition. A depth integrated continuity equation is used to track the deforming free-surface and ensure global mass conservation. A combination of Sommerfeld nonreflecting boundary and dissipation zone methods is implemented at the far end of the reservoir to prevent any back-reflections of pressure and free-surface waves. Nondimensionalized equations are used to compare contribu- tions of each type of force to the development of the hydrodynamic pressure field and to the maximum run-up of free-surface waves on the dam face. Sinusoidal ground accelerations are applied to an idealized dam-reservoir system to analyze the system response. It is observed that the acoustic wave equation solution gives satisfactory results for the pressure field unless the contributions from the free-surface waves become significant at low reservoir depths. The surface wave run-up on the dam face is found to depend on the ground velocity, oscillation period, and the water depth. On the basis of numerical experiments, an expression for the wave run-up to predict conditions of overtopping from probable earthquake characteristics is proposed. DOI: 10.1061/(ASCE)EM.1943-7889.0000322.

Numerical Simulation and Formulation of Wave Run-Up on Dam Face due to Ground Oscillations Using Major Earthquake Acceleration Records

AbstractA previously developed computational model is used for wave run-up analysis in a generic two-dimensional reservoir subjected to major earthquake acceleration records. The model is based on numerical solution of the Navier-Stokes equations and pressure equation considering compressibility effects. An existing model has been revised by the volume of fluid (VOF) method with piecewise linear interface calculation (PLIC) to be able to compute violent wave motion in the reservoir and to predict the maximum wave run-up on the dam crest attributable to ground oscillations during an earthquake. The numerical method and the computer code are validated by comparing the free-surface waves with the data available in the literature. The surface wave run-up on a vertical dam is simulated for different reservoir depths using major earthquake acceleration records. Simulations show that the maximum wave height on a dam body depends on the maximum positive ground velocity. On the basis of dimensional analysis, simul...

Novel Slot-Baffle Design to Improve Mixing Efficiency and Reduce Cost of Disinfection in Drinking Water Treatment

AbstractIn potable water treatment, the commonly used disinfectants are chlorine and ozone. Recently, the use of ozone has gained more acceptance due to its effective disinfectant properties. Howev...