The coastline, as a border where the water flow is relatively impermeable, can change the flow pattern and therefore, the study of its hydrodynamic role is undeniable. in coastal engineering studies and even wet ecosystems even it is simple. In this study, using three-dimensional simulations in the numerical model environment of MIKE 3, the Danish Hydrodynamic Institute, two types of three dimensional simulations have been proposed using Navier Stokes equations to investigate the role of the coastline in rectangular and curved basins. In both simulations, it is assumed that the characteristics of Qeshm's Tidal channel are scientifically established. This study clearly shows that the uniform velocity pattern in a rectangular basin changes with the curvature of coastline on the curved basin. The tightness in the curvature of the basin causes an increase in speed (about 0. 05 m/s) in accordance with the principle of mass conservation. The opening after the turn of the basin causes a decrease of 0. 1 m/s (0. 4 m/s in the rectangular basin to 0. 3 m/s in a curved basin, equivalent to 25% speed). Another point to consider is the role of water level changes. There is not much difference in the speed pattern between Higher High Water (HHW) and Lower Low Water (LLW) in Neap tide, but in the case of Spring tide where the water level is higher, the difference is 0. 1 m/s in the rectangular basin and 0. 2 m/s in the curved shape basin.

Background and Objectives: Increased use of fossil fuels has irreversible consequences such as global warming, ozone depletion, changes in rainfall patterns, sea level rise and detrimental effects on the lives of plants, animals and humans. Today, in many developed countries, energy such as wind and solar as well as marine renewable energy is used to reduce its harmful effects on the environment. The use of these energies is increasing rapidly and countries are studying new plans in this field. Almost all renewable energy comes from the sun, and the energy of the Tidal is an exception. The origin of this phenomenon is related to the gravitational effect of the moon and the sun. Undoubtedly, among the natural phenomena used for energy extraction, the Tidal has the highest continuity and predictability. Methods: Researches show that the Qeshm canal in the Persian Gulf is one of the potential locations for the use of Tidal energy. These turbines can effectively convert Tidal energy into electrical energy. For this purpose, a large-scale three-dimensional model based on finite difference from the Persian Gulf was initially set up, which was validated using observational data including water level and flow velocity. The results of this model were entered into the Qeshm 3D model as input data. The grid of this model is 20 meters. In the areas of Qeshm canal that have the highest flow velocity, a Tidal mraf was established to show the effects of the turbine and an additional term was added to the momentum equations. Findings: In the Qeshm Channel, potential sites were identified. A Tidal farm with 72 horizontal axis turbines was set up and the power output of the farm was investigated for one-month. Based on the modeling results of Delft 3D numerical model, the one-month power output of this field was estimated to be 33. 15 MW. Conclusion: The aim of this study was to investigate the amount of Tidal energy in Qeshm canal. Using a numerical model, energy potential points in Qeshm canal were identified and a Tidal farm was set up in Qeshm canal using porous plates. The amount of energy obtained from this farm was calculated.

Maghrebi has previously introduced a model for the production of isovel contours in a normalized form, which can be used for estimation of discharge in artificial and natural channels. The model is applied to a Tidal river with partially reverse flow, which is caused by opening a sluice gate located asymmetrically close to the right bank of the Ohta floodway in Hiroshima, Japan. An acoustic Doppler current profiler (aDcp) was used to measure the velocity profiles at different verticals and then discharge was calculated. In addition, the estimated discharge based on each measured point and the predicted isovels of flow cross section was obtained. The results show that the corresponding errors for the measured points away from the solid boundaries and the imaginary boundary of the flow between the two adjacent regions with opposite directions, which are associated with lower absolute values of isovels, are reasonable.

For prediction instantaneous energy absorption by axial Tidal turbines in the unsteady water flow a numerical analytical modeling approach has been presented. The purpose of the present article is introducing a fast and stable integral solution method with unique response. This method uses data of computational fluid dynamics in the steady flow to approximate time-dependent performance of axial Tidal turbine in the unsteady external flows. This solution method has been designed for modeling axial Tidal turbine with convergent-divergent duct in water flow with unsteady boundary conditions. The governing equations for fluid flow have been obtained in the form of integral equations. The equation of one-degree of freedom motion of rotor has been solved with fourth-order Runge-Kutta method and variations of parameters method. CFD data for rotor and duct of axial Tidal turbine have been inserted as boundary values in the integral equations of fluid flow. Two time dependent analytical equations were employed for approximation of rotor torque and back pressure coefficient of Tidal turbine. The results of the integral solution method have been compared with time-dependent CFD data in ANSYS-Fluent software. Several numerical simulations were carried out with the presented procedure to determine dimensions of the duct for the most enhancement of power absorption in an axial Tidal turbine.

In this paper, groundwater response to Tidal effects in a Coastal Leaky Aquifer is simulated via analytical solutions. The solutions are obtained by application of separation of variables method and Fourier transform method. It is shown that those points of the aquifer near to the coastal shore are much more influenced by the Tidal fluctuations in the boundary than the rest of the aquifer. The amplitude of Tidal change is significant at points of the aquifer near to the coastal shore and gets smaller with distance from the boundary. In addition, it is shown that groundwater level increases with rises in transmissivity. This phenomenon is more significant when transmissivity is less than 400 m2/hr. Also, the groundwater head rises with rises in recharge rate. The effect of variations in transmissivity and recharge rate on hydraulic head is more significant at points located between 30 and 75 meters and less significant at points near to the coastal shore. The presented analytical solution is compared and verified with those results obtained from MODflow.