Mathematical study of wave interaction with a mound type of composite poroelastic submerged breakwater

2016 ◽  
Vol 124 ◽  
pp. 1-12 ◽  
Author(s):  
Yuan-Jyh Lan ◽  
Tai-Wen Hsu ◽  
Fang-Xuan Gan ◽  
Chi-Yu Li
Author(s):  
Ai-jun Li ◽  
Yong Liu ◽  
Zuo-rui Lyu

This article studies water wave interaction with a submerged quarter-circular breakwater based on potential theory and multipole expansion method. The obliquely and normally incident waves are independently considered. The series solution of velocity potential in the external fluid domain is expressed through the multipole expansions, while the series solution of velocity potential in the quarter-circular internal fluid domain is obtained through the separation of variables. Then, the unknown coefficients in the series solutions are determined by matching the boundary conditions between external and internal fluid domains. The calculation methods for the reflection and transmission coefficients of the submerged quarter-circular breakwater as well as the horizontal and vertical wave forces on the breakwater are presented. The wave forces acting on the submerged breakwater with a seaside quarter-circular-arc and that with a leeside quarter-circular-arc are compared. The hydrodynamic quantities of the submerged quarter-circular breakwater are also compared with those of the submerged semi-circular breakwater. In addition, the effects of breakwater radius, incident frequency, and incident angle on the hydrodynamic quantities of the quarter-circular breakwater are clarified. Valuable results for practical engineering application are drawn.


Author(s):  
Arun Kamath ◽  
Athul Sasikumar ◽  
Hans Bihs

Conventional emerged rubble mound breakwaters are commonly built to protect ports and marinas from direct wave action. With increased high-valued developments in the coastal region, engineers have to design innovative coastal protection structures that can provide adequate harbor tranquility with minimum visual impact. One such solution is the combination of a submerged breakwater with a floating breakwater. In this paper, the open-source CFD model REEF3D (Bihs et al. 2016) is used to simulate wave interaction with a submerged porous breakwater with a floating breakwater on the lee side. The wave interaction with the submerged porous breakwater is validated by comparison with experimental data from Hieu and Tanimoto (2006). The validated model is then used to simulate the wave interaction with a combination of the submerged breakwater and the floating breakwater. The transmission coefficient across the combination is calculated to be about 12.5%, demonstrating the possibility to provide harbor tranquility with minimum visual impact.


2012 ◽  
Vol 1 (33) ◽  
pp. 31 ◽  
Author(s):  
Yuan-Jyh Lan ◽  
Tai-Wen Hsu ◽  
Ching-Yu Chen

In this study, the problem of wave interaction with two closely submerged adjacent porous elastic breakwaters is investigated theoretically. The porous elastic breakwaters are assumed to be homogeneous, isotropic and elastic. Lan and Lee’s (2010) analytical solution is extended to the problem subject to proper boundary conditions. Using general solutions for each region and the matching boundary conditions, a set of simultaneous equations is thus developed and solved numerically. The present analytic solutions compare favorably with simplified cases of the poro-elastic submerged breakwater. Changes of the width of two adjacent breakwaters, the permeable coefficient effect on wave profile, and the effect of materials and configurations of breakwaters on wave variation are the focus of the present paper. The results show that a large amount of energy dissipates when the adjacent structures both have the same soft material and dimension of width with higher permeability. Different materials and shapes of structures could significantly influence the reflection coefficient.


2021 ◽  
Vol 143 (2) ◽  
Author(s):  
R. B. Kaligatla ◽  
Manisha Sharma ◽  
T. Sahoo

Abstract In this article, a coupled model is proposed for wave interaction with a pair of submerged floating tunnels in the presence of an array of bottom-standing trapezoidal porous breakwaters. The theory of Sollitt and Cross is adopted to govern the fluid flow inside the porous medium. For constant water-depth, the eigenfunction expansion method is employed, whereas for varying water-depth, the eigenfunction expansion method along with the mild-slope approximation is employed. The solutions, thus derived, are matched at the shared boundaries under defined physical conditions. First, the performance of a single breakwater of impermeable and permeable type in reducing wave forces on tunnels is analyzed. Next, the performance of two and three submerged breakwaters is studied. The reflection and transmission coefficients of waves are high in the absence of the submerged breakwater and in the presence of an impermeable breakwater. These coefficients significantly reduce in the presence of the submerged porous breakwater. As a result, the horizontal and vertical forces acting on bridges and tunnels are substantially subsided. Wave forces on tunnels reduce with an increase in the angle of incidence. Multiple porous breakwaters show better performance in mitigating wave forces on tunnels. Higher wave force on tunnels is noticed in intermediate water-depth. The findings can enhance the knowledge of submerged porous breakwaters’ performance in reducing wave loads on bridges and tunnels.


Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 261 ◽  
Author(s):  
Yaru Ren ◽  
Min Luo ◽  
Pengzhi Lin

This paper presents a numerical study of the solitary wave interaction with a submerged breakwater using the Consistent Particle Method (CPM). The distinct feature of CPM is that it computes the spatial derivatives by using the Taylor series expansion directly and without the use of the kernel or weighting functions. This achieves good numerical consistency and hence better accuracy. Validated by published experiment data, the CPM model is shown to be able to predict the wave elevations, profiles and velocities when a solitary wave interacts with a submerged breakwater. Using the validated model, the detailed physics of the wave breaking process, the vortex generation and evolution and the water particle trajectories are investigated. The influence of the breakwater dimension on the wave characteristics is parametrically studied.


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