A new method for determination of a wave-ray trace based on tsunami isochrones
A new method for the tsunami wave ray construction is proposed. It is based on isochrones that are built with the use of the wave travel times to a tsunami source. The wave ray approximation is determined as a broken line passing through intersection points of identical time isochrones from two supplementary dot sources. The method was tested on different types of the bottom relief. 1. Methods for the wave ray construction There are a few different methods for the wave rays determination in a non-homogeneous area. The first way is constructing a ray by a numerical solution to the differential equations [1]
Directivity of tsunami generated by subduction zone sources
In a subduction zone, a tsunami source is usually situated above the continental bottom slope. Due to the wave refraction, the opposite slope of a deep water trench works like an optical lens for tsunami waves. The tsunami propagation process is studied using the wave-ray approximation. The tsunami amplitude reduc- tion rate strongly depends on a relative (regarding a trench) location of the initial surface displacement. If the source boundary expands closer to a deep trench axis, then the initially circled front line of the leading tsunami wave will be formed into almost a at shape after passing a trench. The same kind of tsunami behavior can be observed when a wave is generated by a submarine mudslide on a trench slope. A number of hypothetic tsunamis were simulated in the Alaska-Aleutian and in the Kuril{Kamchatka subduction zones. Some locations of possible tsunami sources are estimated as most dangerous for the Hawaiian population and infrastructure. For the most part the tsunamigenic earthquakes occur at subduction zones. The presence of a deep water trench is the main characteristic feature of such a zone. The initial ocean surface displacement (a tsunami source) and earthquake epicenters are mainly located above the continental bottom slope. In Figure 1, the bottom relief (1) of the Kuril{Kamchatka region with historical tsunami source locations is presented (2). The depth at the deep water trench axis is approximately twice as great as an average depth of the Pacic
Simulation and control of hybrid renewable energy system connected to the grid
This paper presents a control and simulation of hybrid renewable energy system connected to the grid. The studied system includes a photovoltaic panel, synchronous permanent magnet generator based wind turbine, and a battery for storage energy. The PV array and wind systems are connected to the common DC bus by a boost converter. The battery is connected by a bi-directional DC/DC converter, and then integrated into the AC utility grid via a common DC/AC inverter. In order to extract the maximum energy, a simulation study has been carried out according to the meteorological conditions (wind speed and variable solar irradiance) while maintaining power quality at a satisfactory level. In order to capture the maximum power, a MPPT algorithm is applied for both wind turbine and photovoltaic panel. The modeling and simulation of the whole system has been performed under Matlab/Simulink environment. The obtained results show that the current and the voltage of grid side are sinusoidal and alternative forms, and the power injected to the grid is around the power produced by the hybrid system.