Numerical study of hydrodynamic mechanism of dynamic tidal power
TL;DR: In this article, the authors explored the hydrodynamic mechanism of the water head across an intended dynamic tidal power dike system using the Delft3D-FLOW software module.
Abstract: Dynamic tidal power is a new way of capturing tidal energy by building a water head using a dike perpendicular to the coast. This study explored the hydrodynamic mechanism of the water head across an intended dynamic tidal power dike system using the Delft3D-FLOW software module. The propagating wave was simulated in a rectangular domain with a horizontal sea bottom at a 30-m depth. A significant water head was created across the dike by blocking the water. The water head increased with increasing dike length and increasing undisturbed tidal current acceleration. The maximum water head for the dike with a length of 50 km, located 900 km from the western boundary, was 2.15 m, which exceeded the undisturbed tidal range. The time series of the water head behaved in a manner identical to the undisturbed tidal current acceleration. The distribution of the water head over the dike assumed an elliptical shape. A parasitic wave was generated at the attachment and scattered outward. The phase lag across the dike did not behave as a linear function of the detour distance.
Citations
More filters
TL;DR: In this article, the authors simulated the dispersion behavior in the coastal waters of tritium discharged from Qinshan nuclear power base, where the sole heavy water reactor is located and the largest trittium amount was discharged in China.
7 citations
TL;DR: In this paper, the authors employed the share ratio approach and established a tidal hydrodynamic model and a water quality diffusion model by the Delft 3D software to perform the numerical simulation.
Abstract: To calculate the environmental capacity of the estuaries of Haizhou Bay in northern Jiangsu, China in 2006 and 2016, this study employed the share ratio approach and established a tidal hydrodynamic model and a water quality diffusion model by the Delft 3D software to perform the numerical simulation. The article compared the environmental capacity in 2006 and 2016, and analyzed the changes between these years. The scenario analysis method was used to explore the influence of factors on the environmental capacity and quantify the contribution of each influencing factor. The results show that the theoretical environmental capacity was reduced by 32.718 tons/day (28.56%) from 114.571 tons/day in 2006 to 81.853 tons/day in 2016. The remaining environmental capacity was reduced by 6.955 tons/day (56.92%) from 12.219 tons/day in 2006 to 5.264 tons/day in 2016. The changes in topography and the amount of runoff into the ocean through the estuaries of Haizhou Bay between 2006 and 2016 reduced the total environmental capacity of the estuaries by an influence ratio of 0.363:0.637. The study will provide the management of the marine environment of Haizhou Bay with information to control the aggregate pollutants flowing into the ocean and support the social and economic sustainable development of Haizhou Bay.
4 citations
TL;DR: In this article, the authors analyzed the changes in the coastline, coastal development, and water quality of Haizhou Bay between 2006 and 2016, and analyzed changes to environmental capacity features, and assessed the influencing factors over this period.
Abstract: Haizhou Bay is an open bay located in northern Jiangsu Province, China. This study analyzes the changes in the coastline, coastal development, and water quality of Haizhou Bay between 2006 and 2016. The box model method and numerical simulation are adopted to calculate the environmental capacities of Haizhou Bay in 2006 and 2016, analyze changes to environmental capacity features, and assess the influencing factors over this period. The scenario analysis method is used to discuss the influencing mechanism and degree of influence of factors (e.g., the water quality difference inside and outside the bay, and sea reclamation) on the environmental capacity and calculate the contribution of each influencing factor. The changes in terrain triggered by sea reclamation and water quality from 2006 to 2016 reduced the total environmental capacity of Haizhou Bay, with an influencing ratio of 0.198:0.802. In other words, poorer water quality inside the bay reduces the environmental capacity by a degree of 4.05 times that of sea reclamation. This study can offer guidance on related future research aiming to protect the marine environment of Haizhou Bay and control the total amount of pollutants discharged into the sea.
3 citations
TL;DR: In this article, the effect of the deep pool on subsurface flow and the salinization of coastal reservoir and adjacent aquifers was investigated and it was shown that a deeper pool and/or a pool located closer to the reservoir dam may enhance the water exchange and salinity level in the reservoir because it accelerates the water/salt inflow to the freshwater body to a greater extent.
Abstract: Coastal reservoirs can alleviate freshwater shortages occurring in the nearshore zone. Deep pools patched at the bottom of reservoirs at greater depths than their adjacent beds maintain a high salinity and possibly provide preferential paths for saltwater backfill. However, such processes are not well understood. Laboratory experiments and numerical simulations were conducted to investigate the effect of the deep pool on subsurface flow and the salinization of coastal reservoir and adjacent aquifers. When seawater intruded into the initially fresh aquifer, the deep pool accelerated the uptake of saltwater to the reservoir from the salt wedge, forming a temporary salt plume around the pool. The saltwater plume also accelerated salt ingress and the evolution of the total salt mass in the coastal reservoir, resulting in the earlier attainment of a quasi-steady state (a classical saltwater wedge) than that when the deep pool was absent. Under steady-state conditions, the deep pool greatly enhanced the exchange of water across the reservoir-aquifer interface by 107% and raised the salinization level of the coastal reservoir by at least 10.3%. Sensitivity analysis suggested that a deeper pool and/or a pool located closer to the reservoir dam may enhance the water exchange and salinity level in the reservoir because it accelerates the water/salt inflow to the freshwater body to a greater extent. These findings may further contribute to improving the predictability and management of water quality in these coastal facilities.
2 citations
TL;DR: In this article, the potential for harnessing tidal power for the limiting case of a coast-connected thin dam is assessed for the case of an island and a small cape of elliptical shape.
Abstract: The tidal waves scattered by a small island and a small cape of elliptical shape are derived by the method of matched asymptotics. The results complement the irrotational flow approximation of the near field by Proudman (Proc. Lond. Math. Soc., vol. 14, 1915, pp. 89–102). The potential for harnessing tidal power is assessed for the limiting case of a coast-connected thin dam.
1 citations
References
More filters
TL;DR: In this paper, a set of MATLAB programs have been written to perform classical harmonic analysis for periods of about 1 year or shorter, account for unresolved constituents using nodal corrections, and compute confidence intervals for the analyzed components.
2,403 citations
TL;DR: Tidal energy has the potential to play a valuable part in a sustainable energy future and is an extremely predictable energy source, depending only on the gravitational pull of the moon and the sun and the centrifugal forces created by the rotation of the earth-moon system as discussed by the authors.
433 citations
TL;DR: Using a three-dimensional hydrodynamic model (ROMS) at ∼1 km spatial resolution, and applying device characteristics of the Seagen-S turbine, this paper showed that the ratio of the amplitudes of the M2 and S2 tidal currents can lead to significant variability in annual practical power generation, which is not accounted for when considering only the mean peak spring tidal velocities.
111 citations
TL;DR: In this paper, an absorbing-generating boundary condition is derived for the two-dimensional-horizontal nonlinear shallow equations using the method of characteristics, which allows the outgoing waves to leave the computational domain through the boundaries with a minimum of reflection, while specifying incoming waves at the same boundaries.
Abstract: An absorbing-generating boundary condition is derived for the two-dimensional-horizontal nonlinear shallow equations using the method of characteristics. It assumes local superposition of the incoming and outgoing long waves at the boundary, and uses a relationship between the flux and surface elevation of the waves. This boundary condition allows the outgoing waves to leave the computational domain through the boundaries with a minimum of reflection, while specifying incoming waves at the same boundaries. The boundary condition's absorbing properties are tested for both linear and nonlinear waves for a range of amplitudes and of angles of incidence. Its performance is compared to the classical Sommerfeld radiation condition for the linear case and is shown to cause significantly less reflection errors, especially for oblique angles. Also, a case of simultaneous absorption and generation of waves at the same boundary is analyzed where it is shown that the errors are of the same order as for the case of ab...
78 citations
TL;DR: In this paper, weakly reflective boundary conditions are derived for the two-dimensional shallow water equations, including bottom friction and Coriolis force, and the essential aspects of the derivation are given.
56 citations