Hossein valipour; gholamreza shams; Elham Ghanbari Adivi; nariman mehranfar
Abstract
Sustainable development, engineering measures and selection of the most appropriate protection method to organize and stabilize the coasts, depends on knowledge of the behavior of waves on the coast.Among the methods of protective structures, we can mention the coastal walls, which weaken the wave passing ...
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Sustainable development, engineering measures and selection of the most appropriate protection method to organize and stabilize the coasts, depends on knowledge of the behavior of waves on the coast.Among the methods of protective structures, we can mention the coastal walls, which weaken the wave passing along the shore by creating damping in the height waves.According to the numerical modeling approach in this study, experimental results were used to evaluate the performance of Open FOAM open source software and K-ω SST turbulence model in modeling the behavior of waves on the body of the coastal dyke.By considering the different conditions for modeling, a total of 45 experiments were selected to run the program. Finally, the results were compared with laboratory findings, which indicates the ability of the numerical model to estimate the height of the wave passing along the shore after colliding with the dyke structure.As the wave height increases, the water height before the structure increases, but its effect on the water height after the structure is greater because at a constant height of the structure, when the wave height increases, the amount of water passing increases.Therefore, when the water height after the structure increases, its difference with the previous height decreases, and therefore the wave damping decreases from a wave height of 6 to 12 cm, and the existing structure reduces the water height to a lesser extent.From the general comparison of the results, it can be said that a structure with a height of 15 cm has a higher efficiency in wave damping and reduces a greater amount of water height.
Fatameh Ghasemi Pirbalouti; Elham Ghanbari Adivi; Rohollah Fattahi; Ehsan Khavasi
Abstract
One of the coastal protection techniques is the use of breakwaters. The aim of this study is to investigate the effect of pile breakwaters on coastal waves, considering rigid cylindrical obstacles on the coastal with constant slope, the effect of their roughness on flow pattern and waves by numerical ...
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One of the coastal protection techniques is the use of breakwaters. The aim of this study is to investigate the effect of pile breakwaters on coastal waves, considering rigid cylindrical obstacles on the coastal with constant slope, the effect of their roughness on flow pattern and waves by numerical modeling in OpenFOAM software was investigated. The method used in flow modeling is RANS method and k-ω, SST model. Modeling was performed in two modes with and without barriers for three different heights of wave. Rigid cylindrical obstacles had a diameter of 0.9 cm and a height of 32 cm. They were contracted at length and width of 45×45 cm and distances of 15×15 cm, with staggered layout. In all three wave heights, the presence of obstacles greatly causes the force of waves to dissipate relative to the unobstructed state. With wave heights of 6, 9 and 12 cm, the obstacles dissipated 47.17, 68.68 and 76.42 percent more than the unobstructed state of wave force, respectively. As the wave height increases, the obstacles have absorbed more force. At wave height of 12 cm, obstacles to wave height of 9 and 6 cm, respectively, 32.35 and 72.45 (compared to no force dimension) absorbed more power. In the discussion of wave mortality in obstacle scenarios compared to unobstructed scenarios, the ability of obstacles to reduce wave height and its mortality averaged 20.88%. The results were compared with laboratory data. The absorbed force for wave height of 6, 9 and 12 cm in numerical model was 17.14, 4.23 and 7.86 percent, respectively, with laboratory model, Also, the mean square root of normal error was 0.07 and correlation coefficient was 0.99, which indicates the conformity of two numerical and laboratory models and the appropriate performance of Open FOAM software in modeling.
مهندسی دریا
Hamed Jalil Masir; Rohollah Fattahi; Elham Ghanbari Adivi
Abstract
Sediment transport phenomenon is considered as one of the important and Effective factors in hydraulic performance and morphological structure of the coasts. In addition, stable development, engineering proceedings and the selection of the most appropriate protection method for organization and stabilization ...
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Sediment transport phenomenon is considered as one of the important and Effective factors in hydraulic performance and morphological structure of the coasts. In addition, stable development, engineering proceedings and the selection of the most appropriate protection method for organization and stabilization of the coast, are depends on the quantity of sediment load. Therefore, the focus of this study is generally to estimate sediment transport rate, assess the impact of coastal forest cover (Green Belt) on decreasing sediment transport rate exposed to tsunami wave trend and to obtain the parametric model to each coastal area using SPSS software. Experiments were performed on the effectiveness of a mangrove tree to reduce tsunami energy, by a simulated polyethylene synthetic shrub structure, for two rectangular and triangular tree layouts, 3 input wave height of 6, 9 and 12 cm, constant and horizontal slope of the coast, 0.35 mm sediment diameter and in terms of presence and absence of cover.. The results of this study show that despite forest cover, 41.17% of coastal erosion and scour are prevented and it helps to stabilization and restoration the coasts. Also considering conditions such as triangular layout selection and increasing cover density, 7.57% and 11.20% respectively, leading to the improvement of the coastal condition. Finally, the parametric model and the experimental equation for estimating the sediment transport rate with the correlation coefficient equal to 0.95, proposed as well.
Elham Ghanbari Adivi
Abstract
In this study, the effect of vegetation on the reduction of the transmitted wave height and beach vegetation to absorb the force of the waves has been studied. Tests for the two layouts with rectangular and triangular spaced 5 × 5 and 10 × 10 cm, 3-state within 10, 30 and 40 cm, 5 sloping ...
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In this study, the effect of vegetation on the reduction of the transmitted wave height and beach vegetation to absorb the force of the waves has been studied. Tests for the two layouts with rectangular and triangular spaced 5 × 5 and 10 × 10 cm, 3-state within 10, 30 and 40 cm, 5 sloping beach., 3, 5, 7 and 10% and 5 wave height of 5/1, 3, 4, 6 and 8 cm were used. In total, 325 different cases have been investigated. 25 of them were been done in no vegetation condition. Dynamic pressure is measured at several points on the coast by a pressure transducer. The force exerted by the waves on the beach of the fuselage has been measured using electronically force meters (load cell) installed in the part of the flume is made movable. The results show that the effect is more rectangular than triangular arrangement of the reduction in wave height.