For laterally complex media, it may be more suitable to take a different orientation of the displacement vector of Shear-WAVEs. This may change the sign of several imaginary reflections and conversion coefficients to be used in reservoir characterization and AVO (Amplitude Versus Offset) analysis or modeling. In this new convention the positive direction of the displacement vector of reflected Shear-WAVEs is chosen to the left of ray tangent (in the direction of WAVE propagation). Therefore, the definition of the displacement vector of shear-WAVEs can be used properly even for very complicated media. Finally the shear-WAVE DYNAMIC behavior of a reservoir zone can be illustrated for laterally varying structures in terms of the amplitude variation and phase behavior using this new orientation.

For a cost-effective design of WAVE screen, an accurate estimation of DYNAMIC pressure and WAVE force is needed. This study investigates the DYNAMIC pressure action on elements of WAVE screen. The WAVE screen consists of several horizontal pipes with constant distance between them. This WAVE screen provides convection, interchanges of seawater within the harbor district, and makes available WAVE energy absorption effectively. The experimental were done on regular WAVEs with 3 heights and 6 periods of WAVEs at a constant water depth of 0. 6 m. Also 3 difference diameters were considered for WAVE screen pipes. DYNAMIC pressures distribution along and around the pipes were measured by the pressure transducers. The results indicated that with increasing of the porosity, the pressure difference was decreased and with increasing of the incident WAVE height, pressure fluctuation for different porosity was increased. Furthermore, the maximum DYNAMIC pressure fluctuation occurred at the angle more than 45° .

One of the important subject in hydraulics and hydrology is flood routing where it could .be achieved by solving Saint-Venant equations. Based on what term is omitted from the momentum equation several methods would be obtained, Kinematic WAVE, Diffusion WAVE and DYNAMIC WAVE. In this study, due to its simplicity compared to the Diffusion WAVE method, Matched diffudivity method has been employed. In order to apply one of the methods, the conditioned the method holds with acceptable accuracy should be determined. In this regard comparison among the three methods has been conducted. In the comparison the effects of different parameters such as channel slope and width, numerical calculation increments, cross section, and the slope of the inflow hydrography, on the outflow hydrograph have been clarified. The objective of this study was to find the cases the different methods are similar or different in results. Generally speaking, increasing the channel slope, reducing its width, and reducing the inflow hydrograph slope results to have close outflow hydrigraphs otherwise the results are significantly different. These conclusions have been obtained for rectangular, trapezoidal. triangular and curricular cross second.

Wind generated sea states are more accurately modeled by short-crested WAVE fields. Whether or not these short-crested WAVEs can induce larger response amplitudes in floating offshore structures is of great concern to offshore engineers. In this paper, the hydroDYNAMICs of a moored semisubmersible in short-crested WAVE fields is investigated. Morison-based motion equations with nonlinear damping terms are used to analyze the DYNAMIC behavior of the structure. A generalized three-parameter short-crested WAVE field is introduced as the incident WAVE. The effect of transverse phase lag, WAVE propagation angle and different ratios of in-line and transverse WAVE numbers are studied on the force and response amplitudes of the floating structure. Finally, the results are compared to that of the long-crested WAVE fields and critical cases are specified.

Due to the lack of measurements in many regions, WAVE characteristics are estimated using different methods. WAVE climate hindcasting/forecasting is mostly conducted by numerical models or empirical methods. Until now, different empirical methods have been developed for WAVE hindcasting. However, with the development of high speed processors, several sophisticated numerical models have been developed for WAVE prediction. These models are mostly phase-averaged spectral WAVE models developed in three generations. In the last two decades, third generation WAVE models have been used widely in academic and practical projects. In this regard, Port and Maritime Organization has produced his own model, PMO DYNAMIC. This model has been developed as a part of first three phases of Monitoring and Modeling of Study of Iranian Coasts project. PMO DYNAMIC package is a software available for engineering purposes. It has several modules that have been developed for different objectives. WAVE model is the module which is used for the generation and transformation of wind WAVEs in coastal areas. In this paper, in order to test the PMO DYNAMIC model capabilities, it has been applied for the prediction of WAVE parameters in Bushehr Bay and the results have been compared with MIKE21 SW model and measured data.

However it is possible to use of numerical methods such as beta-Newmark in order to investigate the structural response behavior of the DYNAMIC systems under random sea WAVE loads but because of necessity to analysis the offshore systems for extensive time to fatigue study it is important to use of simple stable methods for numerical integration. The modified Euler method (MEM) is a simple numerical procedure which can be effectively used for the analysis of the DYNAMIC response of structures in time domain. It is also very effective for response dependent systems in the field of offshore engineering. An important point is investigating the convergence and stability of the method for strongly nonlinear DYNAMIC systems when high initial values for differential equation or large time steps are considered for numerical integrating especially when some frequencies of the system is very high. In this paper the stability of the method for solving differential equation of motion of a nonlinear offshore system (tension leg platform, TLP) under random WAVE excitation is presented. The key point of suitability of MEM for solving the TLP system is that the maximum frequency of the system is about 0.5 Hz. The stability criterion and the convergence of the numerical solution for critical time steps are numerically discussed.

Coasts play an important role in economy of each country for their strategic location for residential, recreational, and industrial activities. Hence, a need has arisen to protect and maintain these coasts against WAVEs and currents. (Rageh et al., 2009). The main cause of damage to coastal structures is the WAVE impact force. Protective structures such as submerged breakwaters, screen breakwaters, and various piles are often designed to provide additional attenuation of the impact force impact. The use of vertical slotted barriers can be a cost effective solution for WAVE energy dissipation when sloped rubble structures are not desirable. For a cost-effective design of such barriers, an accurate estimation of DYNAMIC pressures characteristics is needed. Many experimental and theoretical studies were carried out for determining the DYNAMIC pressures acting on different shapes or structures supported on piles. Neelamani & Sandhya (2005) investigated WAVE reflections, run-up and run-down, and WAVE pressures on plane, dentate and serrated seawalls. Krishnakumar et al. (2010) studied the effect of WAVE screens on the reduction of pressures and forces on a vertical wall on its lee side due to directional WAVEs. Shih (2016) investigated the performance of a pervious pipe screen breakwater installed in front of a seawall in terms of reducing the WAVE impact force and WAVE pressure. The preceding brief review suggests that there is not much experimental data published on the WAVE induced DYNAMIC pressures acting on compound WAVE screen. In this study, experimental investigations on WAVE pressures on different compound WAVE screen configurations were carried out in regular WAVE. The WAVE screen consists of a perforated wall that extends from above the seawater to above the seabed. The gap between pipes allows the seawater exchange, the sediment transport and the fish passage and the results of this study can be used for a better hydroDYNAMIC design of vertical structures...

This paper studies the DYNAMICs of the Mediterranean storm track from the view point of Rossby WAVE activity and its flux. The evolution of WAVE activity is related to WAVE transience and nonconservative effects. In this study, the formulation introduced by Esler and Haynes (1999) has been applyed to compute WAVE activity. The data used for this study are from December 2004 through February 2005. In order to investigate the flux of the WAVE activity into and out of the Mediterranean region, first the WAVE activity and its flux were calculated for each grid point of a grid covering the middle latitudes of the North Atlantic Ocean and the Mediterranean Sea. Next, a two-dimentional rectangular domain at 300 hPa surface as well as a three-dimentional rectangular cubic domain extending from 600 to 200 hPa surfaces was selected on the Mediterranean region, and WAVE activity and its flux were calculated for their different boundaries. These computations were done at 6-hr intervals for each month (December, January and February) of the winter as well as the periods of the two case studies: case 1 (23/12/2004-01/01/2005) with clear propagation of the WAVE packets to the western Mediterranean from the North Atlantic storm track, and case 2 (07/01/2005-13/01/2005) with zonal propagation of the WAVE packets along the central latitude of the North Atlantic storm track. In addition, to investigate more accurately contributions of the different parts of the domains to WAVE activity, each of the domains was divided into three smaller subdomains located on the western, central and eastern Mediterranean. Given the importance of the northern boundary in the WAVE activity flux into the Mediterranean region, the flux of this boundary was studied in more detail. The results indicate that1. Entrance of the WAVE activity was observed in the western and northern boundaries of the two- and three-dimentional domains at all the time scales (monthly, seasonally and during the periods of the case studies), while the eastern and southern boundaries showed the exit of WAVE activity from the Mediterranean region.2. In all of the cases, except Case Study 1, due to the dominance of the total output flux, the Mediterranean region acted as a source of WAVE activity. This result might be regarded, at least partly, as the reason for the existence of various cyclogenesis centers in the Mediterranean region.3. In Case Study 1, due to the dominance of the total input flux, the Mediterranean region acted as a sink of WAVE activity, suggesting high energy transfer from the Atlantic storm track to the Mediterranean region.4. The WAVE activity fluxes associated with the subdomains over the western, central and eastern Mediterranean show that the input flux from the eastern boundary of the subdomains west of the Mediterranean was greater than those from the eastern boundaries of the other subdomains. This finding might be one of the possible reasons for the existence of the main cyclogenesis centers in the western part of the Mediterranean. In this case, the western subdomain acted as a source of the WAVE activity, whereas the central and eastern subdomains played the opposite role.5. In December 2004, it seemed the WAVE activity flux in the western Mediterranean was almost independent of the Atlantic storm track, and most of the influx came from the eastern part of the Mediterranean northern boundary. In January 2005, and to a lesser extent in February, the western Mediterranean was affected by the Atlantic storm track and the major influx belonged to the western part of the Mediterranean region.