scholarly journals Kajian Terhadap Unjuk Kerja Bangunan Pengaman Pantai Dengan Penerapan Simulasi Numerik One Line Model

2015 ◽  
Vol 10 (2) ◽  
pp. 12
Author(s):  
Dalrino - ◽  
Elvi Roza Syofyan

With the position on the west coast region of Sumatra, Padang beach facing directly to Indian Ocean that have potentially threat by the ocean waves that relatively give effect to changes in the coastline. This study was conducted to evaluating the performance of existing coastal protection structure to restrain the rate of erosion as a result of the influence of hydrodynamics process. Condition that reviewed was in form of distance shoreline as simulation results to initial reference line before. One Line Model was conducted to get shoreline change in each time step calculation. Model consists of two conditions, with the absence of coastal structures and with structure respectively. The simulation result show that potential erosion occurs at Batang Arau river mouth with no protection structure. Large erosion predicted around 59.04 meters from the shoreline position early. With coastal protection, model result obtained sedimentation of 7.33 meters coastline from its initial position. This occurs at a distance of 475 meters from the boundary domain. Modeling results also showed erosion is 18.39 meters at a distance of 250 m from the boundary domain. This is likely due to the limited modeling conditions that without reviewing of littoral transport direction that occurred in perpendicular to the coast. Result study show that the presence of a groyne in Padang coasts looks already quite effective in defense of the shoreline of the littoral transport direction, however the installation of groins seemingly did not give significant meaning in the addition of the coastline

Nanoscale ◽  
2021 ◽  
Author(s):  
Shaoqian Hao ◽  
Xie Zhang ◽  
Zheng Li ◽  
Jianlong Kou ◽  
Fengmin Wu

Transport direction of water droplets on a functionalized surface is of great significance due to its wide applications in microfluidics technology. The prevailing view is that a water droplet on...


2021 ◽  
Vol 71 (3) ◽  
pp. 249-263
Author(s):  
Kongeswaran Thangaraj ◽  
Sivakumar Karthikeyan

The focus of this research was to assess the shoreline changes by comparing the satellite data from 1980 to 2020. The study area falls in the region between Kodiakarai and Nagapattinam of the east coast of India, which has frequently been distressed by storm surges and cyclones in the Bay of Bengal. The Digital Shoreline Analysis System (DSAS) detects and measures the erosional and accretional shoreline positions through the statistics of the Shoreline Change Envelope, Net Shoreline Movement, End Point Rate, Linear Regression Rate, and Weighted Linear Regression. The results show that the shoreline from Kodiakkarai to Nagapattinam suffered severe erosion of 17.7% in total with an average annual erosion rate of 3.4 m/year from 1980 to 2020 and the rate of erosion ranged between 0.1 m/year to 19.8 m/year. About 90.5% of the total shoreline was faced high erosion during the period between 2000 and 2010. The maximum erosion was about 1061 m from 2000 to 2010, the maximum accretion was found to be 1002 m in transects at Kodiakkarai during 2010 to 2020. After the effect of 2004 tsunami, the corresponding changes in littoral currents caused the drastic erosion and accretion in this shoreline. The DSAS prediction model shows that 19.3% of the current shoreline will erode in 2030. The maximum predicted erosion is 406 m at Kodiakkarai and the maximum predicted accretion is 148 m at Nagapattinam region. The coastal zone from Kodiakkarai to Nagapattinam needs special attention to prevent the erosion and it is recommended to build suitable coastal protection structures along the coast for sustainable development and to execute the coastal zone management for this region.


1982 ◽  
Vol 120 ◽  
pp. 267-281 ◽  
Author(s):  
Michael De St Q. Isaacson

A numerical method for calculating the interaction of steep (nonlinear) ocean waves with large fixed or floating structures of arbitrary shape is described. The interaction is treated as a transient problem with known initial conditions corresponding to still water in the vicinity of the structure and a prescribed incident waveform approaching it. The development of the flow, together with the associated fluid forces and structural motions, are obtained by a time-stepping procedure in which the flow at each time step is calculated by an integral-equation method based on Green's theorem. A few results are presented for two reference situations and these serve to illustrate the effects of nonlinearities in the incident waves.


Author(s):  
Yanji Wei ◽  
Alan Henry ◽  
Olivier Kimmoun ◽  
Frederic Dias

Bottom hinged Oscillating Wave Surge Converters (OWSCs) are efficient devices for extracting power from ocean waves. There is limited knowledge about wave slamming on such devices. This paper deals with numerical studies of wave slamming on an oscillating flap to investigate the mechanism of slamming events. In our model, the Navier–Stokes equations are discretized using the Finite Volume method with the Volume of Fluid (VOF) approach for interface capturing. Waves are generated by a flap-type wave maker in the numerical wave tank, and the dynamic mesh method is applied to model the motion of the oscillating flap. Basic mesh and time step refinement studies are performed. The flow characteristics in a slamming event are analysed based on numerical results. Various simulations with different flap densities, water depths and wave amplitudes are performed for a better understanding of the slamming.


2019 ◽  
Vol 270 ◽  
pp. 04023
Author(s):  
Asrini Chrysanti ◽  
Mohammad Bagus Adityawan ◽  
Widyaningtyas ◽  
Bagus Pramono Yakti ◽  
Joko Nugroho ◽  
...  

Kulon Progo Airport is an airport development project located in the coastal area near Yogyakarta, Indonesia, which is expected to complete in 2019. With the increase in population, huge land acquisition will be difficult, so the development of coastal areas for the airport became inevitable. Kulon Progo is located in the disaster-prone zone area of the earthquake and tsunami, the airport design must consider the risk management and mitigation from tsunami and earthquake disaster. Although the airport is already calculated the danger of earthquake and tsunami, the development of the coastal area also needs to consider the danger of the natural coastal process itself such as sedimentation and erosion. Shoreline changes due to the new infrastructure in the coastal area can disrupt the equilibrium of coastal process especially the longshore sediment transport. A satellite image shows that Kulon Progo shoreline retreats over 60 meters due to the heavy sediment longshore transport in the past 10 years. Breakwaters in Tanjung Adikarto fishing port also made a great contribution in huge sedimentation behind the infrastructure up to 90 meters. This research will conduct an analysis trough satellite and numerical model to observe the shoreline changes along Kulon Progo Coast. A numerical model shows a high erosion rate along the coast. High sedimentation also observed at the river mouth of Bogowonto and Serang Rivers.


2018 ◽  
Vol 18 (3) ◽  
pp. 241-249
Author(s):  
Cham Dao Dinh ◽  
Minh Nguyen Quang ◽  
Son Nguyen Thai ◽  
Cu Nguyen Van

Research on marine dynamics, including coastal wave motions, is a concern of countries in the world in general and Vietnam in particular. Coastal wave dynamics has a direct impact on human activities including coastal construction, shipping, irrigation, aquatic resources exploitation, etc. The coastal area of Nhat Le, Quang Binh is one of the areas strongly influenced by the coastal wave regime which increases the risk of coastal erosion, estuarine sedimentation, destroys the economic life, affects marine fishing and directly affects the tourist beach area. This article aims to introduce some research results based on the application of MIKE21-SW model of the Danish Hydraulic Institute (DHI) to simulate coastal wave regime in Nhat Le coastal zone, Quang Binh province. The model results are verified by real-time wave data in long-term from the WaMoS® II Radar System at Quang Binh station. The results show that there are many similarities in wave height and direction between the computational model and the actual observation data from the radar system. This result will be an important basis for research and application for coastal protection, reduction in river mouth sedimentation, clearing and flood drainage in the study area.


2012 ◽  
Vol 1 (33) ◽  
pp. 37
Author(s):  
Sutat Weesakul ◽  
Somruthai Tasaduak

Equilibrium bay is a bay that its shoreline is stable and does not change with time in long term. This concept can be applied for coastal protection. Experiments on dynamic equilibrium bay planform are conducted in a laboratory. There is one location of sediment supply source into a bay near upcoast headland and its magnitude vary from case to case. Wave obliquity varies from small to moderate values. These are two main parameters while wave condition is kept constant. The final bay planforms are investigated and recorded once they reach equilibrium with condition that sediment transport gradient approaches zero and no further shoreline change are observed. The parabolic equation similar to that for static equilibrium is newly proposed. The coefficients are originally derived and found to be a function of wave obliquity and the ratio of sediment supplied into bay to longshore sediment transport. The new dynamic equilibrium bay equation can be used and applied to study morphology change with variation of supplied sediment from inland.


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