In single-body converters of ocean wave energy, oscillations of a floating body (buoy) serve as the main driving force for electricity generation. Buoy geometry optimization is known as an approach to enhance the efficiency of these converters. In the present research, the process of wave energy absorption in point absorber converter is modeled as a spring-damper system. Two geometries are considered for the buoy of the converter (conical and spherical-cap). The effects of buoy geometry on its dynamics in the nonlinear wave are investigated and comparison of these effects on dynamic performances of the modeled converter are reported. Equalization of environmental conditions and modeling of the two models were discussed, and a new equalization method was proposed. Effective wave energy on each model was calculated based on geometrical characteristics of the corresponding buoy. Then, the models were hydrodynamically analyzed via boundary element method by taking the diffraction theory as the governing theory. The incident wave was assumed to be a second-order Stokes wave.
Results were obtained in both time and frequency domains and validated against the results of available research. Maximum dynamic responses of the restrained buoy with spherical-cap geometry in heave and surge (vertical and horizontal directions, respectively) were found about 4.4% and 11.3% higher than the conical buoy, respectively. The average percentage of absorbed wave energy by the modeled converter with spherical-cap buoy was about 2.2-2.5% higher than that of the other model. The average percentage of absorbed energy by the models were predicted to range within 20-24%.

Development of wave energy convertors (WEC) is one of the main challenges that naval architectures have encountered, recently. One of the most important approaches before construction of WECs is the evaluation of their conceptual models in computational fluid dynamics (CFD) software. Therefore, in the current article, an innovative model of wave energy convertor is presented and hydrodynamic performance of proposed model in Persian Gulf has been examined. For accurate simulation of dynamics of WEC, mesh morphing technique is utilized. Since the presented WEC is an innovative design and there is no experimental result for validation purpose, it is tried to verify the numerical setup using similar experimental problems which have the various characteristics of the considered problem. Then, several different geometries including flat and foil pedals, and big and small semi-spherical pedals as a part of WEC have been analyzed, numerically. Small semi-spherical pedal has been determined as the best possible geometry. Number of pedals has been another parameter which has been studied and eight pedals model has been recognized as optimum choice. Finally, optimum WEC has been simulated in nine different waves and the results have been presented.

In this study, a new type of wave absorbing seawall is introduced to protect the shoreline against wave induced erosion. The basic design of seawall’s blocks consists of a cubic chamber and back impermeable semicircular wall. The wave energy dissipation coefficient (Kd) was measured to determine the efficiency of the designed structure using physical model. Random waves in wide range of wave heights and periods, with variety of water depth were carried out for the experimental tests. It was observed that the new seawall has significant performance than the rigid seawall in increasing the dissipation of wave energy. The dissipation coefficient for the new seawalls ranges from 0.34 – 0.85, whereas for the rigid wall, it is found to be less than 0.45. In addition, it was found that the wave energy dissipation coefficient increases with the increasing of the wave steepness (Hs/Lp), the relative water depth (d/Lp). Using multiple regression analysis on the measured data in SPSS software, empirical equations have been proposed to predict the energy dissipation coefficient.

During the past few decades, wave energy has received significant attention for harnessing ocean energy. Industry has proposed many topologies such as an oscillating water column, a point absorber, an overtopping system, and a bottom-hinged system. In particular, many researchers have focused on modeling the floating-point absorber, which is thought to be the most cost-efficient technology to extract wave energy. To model such devices, several modeling methods have been used such as the analytical method, the boundary-integral equation method, the Navier-Stokes equations method, and the empirical method. To assist the development of wave energy conversion (WEC) technologies, this report extensively reviews the methods for modeling the floating-point absorber

Liu et al. (1987) proposed a theoretical solution for scattering of waves through a permeable dissipation region. On the basis of bulk dissipation of the incident wave energy, this method is extended to evaluate the reflection and transmission coefficients of waves through a wave filter composed of rows of perforated sheets aligned normally to the direction of wave propagation. The results of the theoretical model are verified by laboratory tests with regular waves.

Today, renewable energy is becoming increasingly important due to the high cost of oil and its unavailability for all communities, as well as the issue of global warming and environmental issues. One of the sources of renewable energy is the energy of the waves of the sea, which can play an important role in the future of energy. In order to exploit the energy of the waves, there is a need to use modern equipment called the wave energy converter to change the wave energy into electrical energy. One of the wave energy converter is Archimedes wave swing. This converter is a well-submerged,fixed-bed equipment in the seabed and it has a simple system compared to other types of converters. its production capacity is remarkable, and its maintenance rates are much lower. In this paper principles of performance and its emergence from the beginning of the idea until now, and the results of the latest research and samples made by this converter have been investigated. In the end, the power output of this type of converter is compared with other converters, and its output power is calculated depending on its controller.

Ocean wave is one of the renewable energy sources that can supply part of the world's energy needs and thus reduce the rate of consumption of fossil fuels and other non-renewable resources. Wave energy converters (WEC) are systems that extract electrical energy from sea waves. For achieving this technology, experimental modelling is of great importance. For hydrodynamically modelling this system and analysing its performance in different conditions, a wave tank is needed to apply sea circumstances to the system. In this study, we investigated experimentally a WEC which was made in Hydrodynamics, Acoustics and Marine propulsion Laboratory at Babol Noshirvani University of Technology. We evaluated the WEC for a wide range of waves in the wave tank. We presented wave characteristics by which the system had appropriate pitch motion and acceptable extracted electrical energy. Moreover, according to data obtained for WEC performance and annual energy diagram of the Caspian Sea, scales 1:5 and 1:6 are selected for making the WEC prototype. Selecting the scales of 1:5 and 1:6, extracted power from the prototypes are about 28 and 53 kilowatts, respectively.

The present study is for the feasibility of using the OWC wave energy converter to supply electrical power to a refinery unit near the shores of the Persian Gulf over a 20-year horizon. Considering the potential of other renewable energy sources in the study area, a combined system of wind turbine, photovoltaic panel, wave converter, electrolyzer, battery and fuel cell is proposed. A comparison between using a reformer instead of an electrolyzer has also been studied. The effect of OWC energy converters on the hybrid system has been evaluated as a new approach in generating the required power. The results show that the hybrid system including the OWC converter with NPC and COE costs $ 26.5 and $ 0.205, respectively, is more cost-effective than the hybrid system without the OWC converter to meet the refinery unit power demand. About 30.7% of the required power is supplied by the wave energy converter. The use of wave energy converters is reduced in the months with low wave energy potential and the role of other renewable energy sources becomes more colorful.

The risk of landslides in water structures and dams is significant due to the directand indirect effects of water on the occurrence of landslides. When granular orsolid materials slide into a body of water such as a reservoir, lake, or sea, massmomentum is transferred to the water mass, creating waves with large amplitudes.This phenomenon is known as an impulsive wave in a reservoir or lake or as alandslide tsunami in the ocean and sea. in this experimental study Due to the many parameters affecting thecharacteristics of the wave and the complexity of the problem, there is a need forextensive investigations in this field. In the present research, the waves created bylandslides in the reservoirs of dams and the characteristics of the waves created inthe dam reservoir, such as the length of the wave and the directions of wavepropagation, are investigated. The results showed that the highest wave energy in model 3 (13.258 kJ) occurred at a reservoir depth of 55 cm.