مهندسی عمران شریف (Aug 2021)
Numerical simulation of wave generation in a tank by wall and floor oscillation
Abstract
Tsunamis occur every year in different seas and oceans around the world. These waves propagate at high speeds in various directions and, if they reach the shore, cause irreparable damage to these areas and their structures and facilities. Therefore, understanding this complex phenomenon and predicting its behavior can reduce the damages. In the present study, numerical simulation studies of the tsunami phenomenon were carried out. The purpose of the study was to predict the tsunami wave characteristics when reaching the coastal area. The use of numerical simulation greatly reduces the cost of laboratory work and can also be used for complex geometries and models. The tsunami waves were considered as viscous fluid by Navier-Stokes equations for shallow water as governing equations with fluid volume fractionation method for simulating water surface in software. Wave generation was created by simulating a tank that fluctuates once to its left wall and once to its bottom. This work was carried out by Fluent software. In the following, the influence of shaking side wall angles on the generated waves is investigated. The simulation results show a significant increase in wave height due to the oscillating wall angle. The effects of the oscillating bottom wall have also been studied. In this thesis, the method of producing and propagating tsunami waves is described and the equations are defined. Also, since the most important issue in dealing with this phenomenon is their control, a method for controlling tsunami waves is presented in this thesis. Finally, a multi-phase method is used to simulate the movement of waves in a tank with a tremor wall. Finally, the obtained results have been compared to the analytical results by Green equation method and there are good agreements between them. The results showed that there is no change in wave height at distant points and with the oblique wall obliquity being increased by 30 degrees, the wave production increases. In addition, the flow and pressure lines also become almost horizontal.
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