scholarly journals BOUSSINESQ-TYPE EQUATIONS WITH VARIABLE COEFFICIENTS FOR NARROW-BANDED WAVE PROPAGATION FROM ARBITRARY DEPTHS TO SHALLOW WATERS

2012 ◽  
Vol 1 (33) ◽  
pp. 5
Author(s):  
Gonzalo Simarro ◽  
Alvaro Galan ◽  
Alejandro Orfila

A fully nonlinear Boussinessq-type model with 7 Nwogu’s α-like coefficients is considered. The model is one-layer and low-order to simplify the numerical solvability. The coefficients of the model are here considered functions of the local water depth so as to allow an improvement of the dispersive properties for narrow banded trains in very deep waters. The proposed model is fully nonlinear in weakly dispersive conditions, so that nonlinear wave decomposition in shallower waters is well reproduced.

2011 ◽  
Vol 1 (32) ◽  
pp. 48 ◽  
Author(s):  
Rodrigo Cienfuegos ◽  
L. Duarte ◽  
L. Suarez ◽  
P. A. Catalán

We present experimental and numerical analysis of nonlinear processes responsible for generating infragravity waves in the nearshore. We provide new experimental data on random wave propagation and associated velocity profiles in the shoaling and surf zones of a very mild slope beach. We analyze low frequency wave generation mechanisms and dynamics along the beach and examine in detail the ability of the fully nonlinear Boussinesq- type model SERR1D (Cienfuegos et al., 2010) to reproduce the complex dynamics of high frequency wave propagation and energy transfer mechanisms that enhance infragravity wave generation in the laboratory.


2012 ◽  
Vol 138 (5) ◽  
pp. 362-371 ◽  
Author(s):  
A. Galan ◽  
G. Simarro ◽  
A. Orfila ◽  
J. Simarro ◽  
P. L.-F. Liu

2020 ◽  
Vol 14 (3) ◽  
pp. 7082-7093
Author(s):  
Jahirwan Ut Jasron ◽  
Sudjito Soeparmani ◽  
Lilis Yuliati ◽  
Djarot B. Darmadi

The hydrodynamic performance of oscillating water column (OWC) depends on the depth of the water, the size of the water column and its arrangement, which affects the oscillation of the water surface in the column. An experimental method was conducted by testing 4 water depths with wave periods of 1-3 s. All data recorded by the sensor is then processed and presented in graphical form. The research focused on analyzing the difference in wave power absorption capabilities of the three geometric types of OWC based on arrangements of water columns. The OWC devices designed as single water column, the double water column in a series arrangement which was perpendicular to the direction of wave propagation, and double water column in which the arrangement of columns was parallel to the direction of wave propagation. This paper discussed several factors affecting the amount of power absorbed by the device. The factors are the ratio of water depth in its relation to wavelength (kh) and the inlet openings ratio (c/h) of the devices. The test results show that if the water depth increases in the range of kh 0.7 to 0.9, then the performance of the double chamber oscillating water column (DCOWC) device is better than the single chamber oscillating water column (SCOWC) device with maximum efficiency for the parallel arrangement 22,4%, series arrangement 20.8% and single column 20.7%. However, when referring to c/h, the maximum energy absorption efficiency for a single column is 27.7%, double column series arrangement is 23.2%, and double column parallel arrangement is 29.5%. Based on the results of the analysis, DCOWC devices in parallel arrangement showed the ability to absorb better wave power in a broader range of wave frequencies. The best wave of power absorption in the three testing models occurred in the wave period T = 1.3 seconds.


2014 ◽  
Vol 60 (1-4) ◽  
pp. 87-105 ◽  
Author(s):  
Ryszard Staroszczyk

Abstract The paper is concerned with the problem of gravitational wave propagation in water of variable depth. The problem is solved numerically by applying an element-free Galerkin method. First, the proposed model is validated by comparing its predictions with experimental data for the plane flow in water of uniform depth. Then, as illustrations, results of numerical simulations performed for plane gravity waves propagating through a region with a sloping bed are presented. These results show the evolution of the free-surface elevation, displaying progressive steepening of the wave over the sloping bed, followed by its attenuation in a region of uniform depth. In addition, some of the results of the present model are compared with those obtained earlier by using the conventional finite element method.


1972 ◽  
Vol 21 (0) ◽  
pp. 01-13 ◽  
Author(s):  
Pierre Ch. Montouchet

A consultation of the original descriptions of the genera of Scissurellidae led the author to conclude that the valid names for the genera of this family are: Scissurella d'Orbigny, 1823 (redescription by Sowerby, 1824), Anatoma Woodward, 1859, Inoisura Hedley, 1904, Scissurona Iredale, 1924, Sinezona Finlay, 1927. Scissurella and Anatoma are cosmopolites, the first generally living in shallow waters, associated to sea-weeds, while the second is found in deep waters. The three last genera are restricted to Australasia. Three new species are described from the Brazilian coast: Soissu rella alexandrei, Scissurella eleotilis and Scissurella morretesi. The internal anatomy of S. alexandrei is described. These three new species have been found in littoral shallow waters, the two first on the northeast Brazilian coast, the third on the coast of the State of São Paulo. The fourth known species of Scissurellidae from Brazil, Anatoma aedonia (Watson, 1886), was dredged by H.M.S, "Challenger", in 1873, off Pernambuco, 350 fm (640 m).


2016 ◽  
Vol 715 ◽  
pp. 180-185 ◽  
Author(s):  
Masniezam Ahmad ◽  
Khairul Azwan Ismail ◽  
Fauziah Mat ◽  
William James Stronge

This study proposes an improved viscoplastic impact model that calculates impact response for direct impact between two compact bodies. The proposed model employs spring and viscous elements that represent the energy loss due to plastic deformation and stress wave propagation, respectively. The impact response is calculated by solving differential equations through analytical and numerical methods. This model can accurately predict impact response for low, moderate and high impact speeds.


Zootaxa ◽  
2010 ◽  
Vol 2603 (1) ◽  
pp. 65
Author(s):  
JOSE MARIA AGUILAR-CAMACHO ◽  
JOSE LUIS CARBALLO

Chalinidae is a family of haplosclerid sponges with a delicate reticulated chaonosomal skeleton of uni-, pauci- or multispicular primary lines which are connected by unispicular secondary lines, and with an ectosomal skeleton, if present, formed by a regular hexagonal, unispicular, tangential reticulation (Weerdt 2002). Currently, the family harbors only five valid genera (Chalinula, Cladocroce, Dendrectilla, Dendroxea and Haliclona; Soest et al. 2008), although recent molecular studies suggest that a new rearrangement of the present classification is needed (Redmond et al. 2007). Cladocroce was described by Topsent (1892) from specimens collected in the Atlantic Ocean. The principal characteristic of this genus is the presence of multispicular fiber tracts with a rather dense subisotropic reticulation in between (Weerdt 2002). After that, 10 species have been described, most of them from deep waters and cold climates (Putchakarn et al. 2004). Only three species have been found living in shallow waters: C. aculeata Pulitzer-Finali, 1982 from the Great Barrier Reef, C. burapha Putchakarn et al., 2004 from the Gulf of Thailand, and C. tubulosa Pulitzer-Finali, 1993 from the port of Mombasa, in Kenya. Sponge taxonomy studies in the Mexican Pacific coast have been focused mainly on hadromerids, and particularly on boring sponges (Carballo et al. 2008), and the current knowledge of haplosclerids is very scarce (Cruz-Barraza & Carballo 2006). In this paper, a new species of Cladocroce is described and compared with the other species recorded worldwide. With this contribution the genus Cladocroce increases to 12 species.


2019 ◽  
Vol 123 ◽  
pp. 127-147 ◽  
Author(s):  
Juan Carlos Muñoz ◽  
Michael Ruzhansky ◽  
Niyaz Tokmagambetov

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