Nonlinear Effect on Wave-Structure Interaction

Author(s):  
J. M. Chen ◽  
D. Liang

Accurate prediction on the behaviour of the nonlinear waves in a coastal environment is vital to the safe design and performance of coastal defence. This paper is concerned with the description of tsunami wave-island interaction, and includes both linear and nonlinear modelling of the maximum free surface motion arising within distorted flow field. A deterministic nonlinear effect on the predicted maximum runup is examined using a Boussinesq-type model. Statistics of the predicted maximum leading-crest motion are obtained and discussed in light of linear diffraction theory. The results show that the predicted maximum runup and free surface motion by the quaternary-islands is affected by nonlinear wave transformation. The numerical simulations suggest that the present model describes the wave field very accurately even for extreme events. The present study provides a critical insight into the free surface elevation maxima at surf zone, thus safeguarding the structure design.

2016 ◽  
Vol 23 (s1) ◽  
pp. 44-51 ◽  
Author(s):  
Qian-lu Xiao ◽  
Chun-hui Li ◽  
Xiao-yan Fu ◽  
Mei-ju Wang

Abstract The transformation during wave propagation is significantly important for the calculations of hydraulic and coastal engineering, as well as the sediment transport. The exact wave height deformation calculation on the coasts is essential to near-shore hydrodynamics research and the structure design of coastal engineering. According to the wave shoaling results gained from the elliptical cosine wave theory, the nonlinear wave dispersion relation is adopted to develop the expression of the corresponding nonlinear wave shoaling coefficient. Based on the extended elliptic mild slope equation, an efficient wave numerical model is presented in this paper for predicting wave deformation across the complex topography and the surf zone, incorporating the nonlinear wave dispersion relation, the nonlinear wave shoaling coefficient and other energy dissipation factors. Especially, the phenomenon of wave recovery and second breaking could be shown by the present model. The classical Berkhoff single elliptic topography wave tests, the sinusoidal varying topography experiment, and complex composite slopes wave flume experiments are applied to verify the accuracy of the calculation of wave heights. Compared with experimental data, good agreements are found upon single elliptical topography and one-dimensional beach profiles, including uniform slope and step-type profiles. The results indicate that the newly-developed nonlinear wave shoaling coefficient improves the calculated accuracy of wave transformation in the surf zone efficiently, and the wave breaking is the key factor affecting the wave characteristics and need to be considered in the nearshore wave simulations.


Author(s):  
Vincent Gruwez ◽  
Ine Vandebeek ◽  
Dogan Kisacik ◽  
Maximilian Streicher ◽  
Corrado Altomare ◽  
...  

This paper introduces the 2D experiments conducted for the CREST project in the wave flume of Ghent University. The experiments focus on wave interactions with low-crested sea dikes fronted by a shallow foreshore and mildly to steeply sloping beaches, which is a very typical situation along the Belgian coast. Foreshore slopes of 1/20, 1/35, 1/50 and 1/80 were tested for a range of low to high energy wave conditions, a variation in wave steepness and two water levels. The main goal was to obtain a dataset in which the effects of the infragravity waves on the wave-structure interactions (i.e. wave overtopping and impact forces) can be studied. The tests included high spatial resolution surface elevation measurement tests, which is new for beaches including a dike in the inner surf zone. From the first results it became clear that the foreshore slope influences the wave transformation up to the dike toe. The influence is apparent comparing to existing (semi-) empirical models for prediction of the spectral wave period at the dike toe and wave overtopping at the dike crest. The high spatial resolution data show a steep increase in infragravity significant wave height in the very shallow area in front of the dike.


2012 ◽  
Vol 1 (33) ◽  
pp. 28 ◽  
Author(s):  
Marion Tissier ◽  
Philippe Bonneton ◽  
Gerben Ruessink ◽  
Fabien Marche ◽  
Florent Chazel ◽  
...  

Recent field studies over low sloping beaches have shown that infragravity waves could dissipate a significant part of their energy in the inner surf zone. This phenomenon and the associated short- and long-wave transformations are not well-understood. In this paper, we assess the ability of the fully nonlinear Boussinesq-type model introduced in Bonneton et al. (2011) to reproduce short and long wave transformation in a case involving a strong infragravity wave dissipation close to the shoreline. This validation study, based on van Dongeren et al. (2008)’s laboratory experiments, suggests that the model is able to predict infragravity wave breaking as well as the complex interactions between short and long waves in the surf zone.


1995 ◽  
Vol 17 (4) ◽  
pp. 6-12
Author(s):  
Nguyen Tien Dat ◽  
Dinh Van Manh ◽  
Nguyen Minh Son

A mathematical model on linear wave propagation toward shore is chosen and corresponding software is built. The wave transformation outside and inside the surf zone is considered including the diffraction effect. The model is tested by laboratory and field data and gave reasonables results.


2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Mohammed Al-Smadi ◽  
Nadir Djeddi ◽  
Shaher Momani ◽  
Shrideh Al-Omari ◽  
Serkan Araci

AbstractOur aim in this paper is presenting an attractive numerical approach giving an accurate solution to the nonlinear fractional Abel differential equation based on a reproducing kernel algorithm with model endowed with a Caputo–Fabrizio fractional derivative. By means of such an approach, we utilize the Gram–Schmidt orthogonalization process to create an orthonormal set of bases that leads to an appropriate solution in the Hilbert space $\mathcal{H}^{2}[a,b]$ H 2 [ a , b ] . We investigate and discuss stability and convergence of the proposed method. The n-term series solution converges uniformly to the analytic solution. We present several numerical examples of potential interests to illustrate the reliability, efficacy, and performance of the method under the influence of the Caputo–Fabrizio derivative. The gained results have shown superiority of the reproducing kernel algorithm and its infinite accuracy with a least time and efforts in solving the fractional Abel-type model. Therefore, in this direction, the proposed algorithm is an alternative and systematic tool for analyzing the behavior of many nonlinear temporal fractional differential equations emerging in the fields of engineering, physics, and sciences.


1995 ◽  
Vol 32 (1) ◽  
pp. 177-183 ◽  
Author(s):  
Y. Kamotani ◽  
L. Chao ◽  
S. Ostrach ◽  
H. Zhang
Keyword(s):  

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Richard Angelous Kotey ◽  
Richard Akomatey ◽  
Baah Aye Kusi

PurposeThis study examines the possible nonlinear effect of size on stakeholder and shareholder profitability in the Ghanaian insurance brokerage industry.Design/methodology/approachThis study employs a panel dataset of 64 Ghanaian insurance brokerage firms spanning 2011–2015. Static [ordinary least squares (OLS), fixed effect and random effect and dynamic (two-step generalized method of moments (GMM))] estimation techniques are employed to analyze the data.FindingsThe study finds the existence of both economies and diseconomies of scale and scope theories in the Ghanaian insurance brokerage industry confirming the existence of nonlinear nexus between size and performance. This finding is consistent for both stakeholder and shareholder profit performance. Thus, the results show that size improves profitability of insurance brokerage firms, but beyond a certain threshold, the relationship turns negative as size negatively affects profitability.Practical implicationsThe research findings have implications for both policy and research; the study recommends that Ghanaian brokerage managers should understand that not all growth is good and exercise a duty of care when applying growth strategies by monitoring size effect on performance so as not to go beyond the inflection point. Further research can be done to examine this effect in other contexts, timeframes and jurisdictions.Originality/valueThis research is unique in that it employs a panel dataset consisting of 96% of insurance brokerage firms in Ghana whilst employing both static and nonstatic regression models to examine the effect of size. The research analysis adopted is robust, and the findings are significant. Also, the lack of empirical studies on the operations and dealings of auxiliary institutions such as the insurance brokerage firms adds value to this research.


2021 ◽  
pp. 87-126
Author(s):  
Ushe Chipengo ◽  
Niru K. Nahar ◽  
John L. Volakis ◽  
Alan D. R. Phelps ◽  
Adrian W. Cross

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