Forty-year investigation of wave power in energetic region of Persian Gulf in Iranian territorial waters by using short-term and new long-term stability assessment parameters

The wave power in high potential area of the northern Persian Gulf(near to Iranian coastal areas)is assessed by taking into account the temporal and spatial distributions of wave power for a period of forty years.For this purpose,assimilated wind data of European Centre for Medium-Range Weather Forecasting Interim Reanalysis(ERA-Interim),and hydrography data of General Bathymetric Chat of the oceans(GEBCO)are used as SWAN model.Seven locations are investigated in the study area by considering the amount of coefficient of variation,the amount of average annual power,and the short-term and a new long-term(decadal variability index)power stability assessment parameters.The results showed more stability in the eastern parts of the study area and concluded that a narrow line between the point which is in the middle and another point which is in the eastern middle part of the study area may be the best locations for more investigation and the feasibility study for energy converter farms.Also,it is found that the middle part of the study region with about 2.5 kW/m power is the most energetic area.It is concluded that the dominant direction of wave power distribution in all points is the northeast,and this dominant direction has not changed during the forty-year period.It is observed that the mean annual energy increases with a slight slope in the total 40 a,and this increasing trend is more obvious in the fourth decade.Although it is observed that the wave power of the second decade has the most stability and the least variation,the wave power in the fourth decade has the most variation.Moreover,the results showed that the study region’s wave power increase by approximately a mean change rate of 0.027 kW/(m·a);and the maximum change rate of wave power was in the northwest part and the minimum change rate of wave power was in the southeast part which were about 0.036 kW/(m·a)and 0.014 kW/(m·a),respectively.

Modeling of the Changes in Flow Velocity on Seawalls under Different Conditions Using FLOW-3D Software

Seawalls are among protective structures that are constructed for decreasing the level of wave force and/or protecting from other structures. In this regard, more accurate investigation of these structures takes great importance from different perspectives. This research investigates the change of the velocity on seawall crown by considering the obstacles in different layouts and slopes. FLOW-3D has been used in this research for modeling. The results of the modeling show that the existence of obstacles has a determinative role in decreasing flow rate in the crown of seawalls. Also, as it was expected, the slope factor on upstream seawalls is very determinative in decreasing this rate such that the lowest velocity on the wall occurs in D-state layout and the slope of 45°.

Spectral Wave Modeling in Very Shallow Water at Southern Coast of Caspian Sea

This study evaluates the capability of the Simulating WAves Nearshore(SWAN)wave model(version 41.01)in predicting significant wave height and spectral peak energy content for swell waves in very shallow water of surf zone during depth-induced wave breaking and dissipation.The model results were compared with field measurements at five nearshore stations.The results demonstrated that some breaker index formulations were successful for significant wave height prediction in surf zones.However,an incorrect shape of the energy spectrum and overestimated near spectral peak energy content at shallow water stations were obtained using all of the embedded depth-induced wave breaking formulations in SWAN.The dependent breaker index on relative depth(Kpd)formulation,which was successful in predicting near spectral peak energy content,resulted in an average error of 30%.Finally,this formulation was modified to enhance the model performance in reproducing the spectral peak energy content.