Numerical study on S-wave transmission across a rough, filled discontinuity

The process of pressure wave transmission in liquid is simulated with the moving particle semi-implicit (MPS) method. The simulation is carried out in a tube full filled with an energy absorbing liquid. Here we studied the shapes and positions of pressure waves and investigated the behavior of the waves under different viscosities and densities of liquids. Some typical parameters of pressure wave, such as peak pressure value, wave length and transport speed are studied. Varying viscosity does not change the wave length and speed of the pressure wave evidently. The effect of interfaces which formed by viscosity difference or density difference is investigated. Reflection is found not always happened on such interfaces. Pressure wave transport to liquid-solid interface and free surface are also simulated. Pressure wave is vanished when closing to free surface. These results give useful qualitative suggestions on controlling the pressure wave in fluid engineering.

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Neutron-nucleus optical model parameter effects on s-wave transmission coefficients

Nuclear Physics ◽

10.1016/0029-5582(64)90357-8 ◽

1964 ◽

Vol 57 ◽

pp. 603-610 ◽

Cited By ~ 3

Author(s):

E.H. Auerbach ◽

C.E. Porter

Keyword(s):

Optical Model ◽

Wave Transmission ◽

S Wave ◽

Model Parameter ◽

Transmission Coefficients ◽

Optical Model Parameter ◽

Wave Transmission Coefficients

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Numerical study of Rayleigh wave transmission through an acoustic barrier

Journal of Applied Physics ◽

10.1063/1.3130405 ◽

2009 ◽

Vol 105 (11) ◽

pp. 114902 ◽

Cited By ~ 2

Author(s):

Ebrahim Lamkanfi ◽

Nico F. Declercq ◽

Wim Van Paepegem ◽

Joris Degrieck

Keyword(s):

Rayleigh Wave ◽

Numerical Study ◽

Wave Transmission

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Numerical study on the generation of downgoing S‐waves by a vertical force acting close to a step‐like topography

Geophysics ◽

10.1190/1.1443939 ◽

1996 ◽

Vol 61 (1) ◽

pp. 192-201 ◽

Cited By ~ 5

Author(s):

Toshiaki Yokoi

Keyword(s):

Numerical Study ◽

Vertical Force ◽

S Wave ◽

S Waves ◽

Mountain Ranges ◽

Remote Areas ◽

Vertical Seismic Profiling ◽

Unbounded Medium ◽

Vertical Impact

I present detailed numerical experiments on a recently proposed S‐wave generation method and show the excitation characteristics of the downgoing S‐wave caused by a vertical impact acting close to a step‐like topography. The geophysicists’ group of Akita University recently studied and confirmed this phenomenon by in‐situ measurements and named it the “pit effect.” The numerical simulation is performed in 2-D space by the indirect boundary‐element method using the Green’s function for a homogeneous unbounded medium. The results show that the pit effect is a practical S‐wave generator vertical seismic profiling (VSP) and refraction surveys. The generation of a vertical downgoing S‐wave does not require any special machinery, so the pit effect can be used in many situations and especially in remote areas and difficult enviroments such as swamps and steep mountain ranges.

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s-wave quasiparticle resonance in neutron-rich drip-line nuclei

Progress of Theoretical and Experimental Physics ◽

10.1093/ptep/ptz136 ◽

2020 ◽

Vol 2020 (1) ◽

Author(s):

Yoshihiko Kobayashi ◽

Masayuki Matsuo

Keyword(s):

Elastic Scattering ◽

Single Particle ◽

Numerical Study ◽

Bound State ◽

Particle Energy ◽

Drip Line ◽

Coordinate Space ◽

Particle State ◽

S Wave ◽

S Matrix

Abstract We investigate unbound single-particle states in pair-correlated drip-line nuclei by describing a low-energy elastic scattering of a neutron in the $s$-wave within the framework of the coordinate space Hartree–Fock–Bogoliubov (Bogoliubov–de Genne) equation. A numerical study is performed for a neutron drip-line carbon isotope where the neutron $2s_{1/2}$ orbit is located close to zero energy. Analyzing the S-matrix poles of the elastic scattering, we discuss properties of the $s$-wave quasiparticle resonance and, in particular, behaviors characteristic to drip-line nuclei. It is found that the S-matrix has two pairs of poles; one pair appears as either a weakly bound state, a virtual state or a resonance while the other pair makes a contribution analogous to a bound single-particle state. The $s$-wave quasiparticle resonance emerges with a large variation depending on the pairing gap and the single-particle energy of the $s$-orbit.

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Wave and Hydrodynamic Processes in the Vicinity of a Rubble-Mound, Permeable, Zero-Freeboard Breakwater

Journal of Marine Science and Engineering ◽

10.3390/jmse8030206 ◽

2020 ◽

Vol 8 (3) ◽

pp. 206

Author(s):

Theofano I. Koutrouveli ◽

Athanassios A. Dimas

Keyword(s):

Wave Reflection ◽

Stokes Equations ◽

Numerical Study ◽

Flow Behavior ◽

Wave Transmission ◽

Leeward Side ◽

Empirical Formulas ◽

Wave Setup ◽

Breaking Parameter ◽

Rubble Mound

A numerical study for the effect of crest width, breaking parameter, and trunk permeability on hydrodynamics and flow behavior in the vicinity of rubble-mound, permeable, zero-freeboard breakwaters (ZFBs) is presented. The modified two-dimensional Navier-Stokes equations for two-phase flows in porous media with a Smagorinsky model for the subgrid scale stresses were solved numerically. An immersed-boundary/level-set method was used. The numerical model was validated for the cases of wave propagation over a submerged impermeable trapezoidal bar and a low-crested permeable breakwater. Five cases of breakwaters were examined, and the main results are: (a) The size of the crest width, B, does not notably affect the wave reflection, vorticity, and currents in the seaward region of ZFBs, while wave transmission, currents in the leeward side, and mean overtopping discharge all decrease with increasing B. A non-monotonic behavior of the wave setup is also observed. (b) As the breaking parameter decreases, wave reflection, transmission, currents, mean overtopping discharge, and wave setup decrease. This observation is also verified by relevant empirical formulas. (c) As the ZFB trunk permeability decreases, an increase of the wave reflection, currents, wave setup, and a decrease of wave transmission and mean overtopping discharge is observed.

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