scholarly journals A NUMERICAL MODEL FOR WAVE PROPAGATION OVER MUDDY SLOPE

2011 ◽  
Vol 1 (32) ◽  
pp. 27 ◽  
Author(s):  
Xiaojing Niu ◽  
Xiping Yu
Keyword(s):  
Wave Propagation ◽  
Numerical Model ◽  
Reasonable Agreement ◽  
Present Model ◽  
Equations Of Motion ◽  
Free Water ◽  
Incompressible Fluids ◽  
Volume Of Fluid Method ◽  
Governing Equations ◽  
Smac Method

A numerical model for the interaction between waves and muddy seabed is developed, in which the motion of the movable mud and the motion of water are solved simultaneously. The governing equations for both water and the mud are the continuity equation and the equations of motion for incompressible fluids. Water is treated as a Newtonian fluid, while a visco-elastic-plastic model is used to describe the rheology of the mud. Both the interface between water and the mud and the free water surface are traced by the VOF (Volume of Fluid) method. The numerical method is based on the well-known SMAC method. The numerical model is applied to simulate wave propagation over a muddy slope, and the numerical results are in reasonable agreement with the experimental data. The present model is proved better performance than the traditional analytic model in case that topography change is not negligible.

scholarly journals Numerical Investigations of Tsunami Run-Up and Flow Structure on Coastal Vegetated Beaches

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1776 ◽  
Author(s):  
Hongxing Zhang ◽  
Mingliang Zhang ◽  
Tianping Xu ◽  
Jun Tang
Keyword(s):  
Wave Propagation ◽  
Numerical Model ◽  
Peak Flow ◽  
Tsunami Wave ◽  
Coastal Vegetation ◽  
Coastal Forest ◽  
Governing Equations ◽  
Tsunami Waves ◽  
Run Up ◽  
Sloping Beach

Tsunami waves become hazardous when they reach the coast. In South and Southeast Asian countries, coastal forest is widely utilized as a natural approach to mitigate tsunami damage. In this study, a depth-integrated numerical model was established to simulate wave propagation in a coastal region with and without forest cover. This numerical model was based on a finite volume Roe-type scheme, and was developed to solve the governing equations with the option of treating either a wet or dry wave front boundary. The governing equations were modified by adding a drag force term caused by vegetation. First, the model was validated for the case of solitary wave (breaking and non-breaking) run-up and run-down on a sloping beach, and long periodic wave propagation was investigated on a partially vegetated beach. The simulated results agree well with the measured data. Further, tsunami wave propagation on an actual-scale slope covered by coastal forest Pandanus odoratissimus (P. odoratissimus) and Casuarina equisetifolia (C. equisetifolia) was simulated to elucidate the influence of vegetation on tsunami mitigation with a different forest open gap. The numerical results revealed that coastal vegetation on sloping beach has significant potential to mitigate the impacts from tsunami waves by acting as a buffer zone. Coastal vegetation with open gaps causes the peak flow velocity at the exit of the gap to increase, and reduces the peak flow velocity behind the forest. Compared to a forest with open gaps in a linear arrangement, specific arrangements of gaps in the forest can increase the energy attenuation from tsunami wave. The results also showed that different cost-effective natural strategies in varying forest parameters including vegetation collocations, densities, and growth stages had significant impacts in reducing the severity of tsunami damage.

Influence of micro-length-scale parameters and inhomogeneities on the bending, free vibration and wave propagation analyses of a FG Timoshenko’s sandwich piezoelectric microbeam

2017 ◽  
Vol 21 (4) ◽  
pp. 1243-1270 ◽  
Author(s):  
Mohammad Arefi ◽  
Ashraf M Zenkour
Keyword(s):  
Wave Propagation ◽  
Free Vibration ◽  
Equations Of Motion ◽  
Strain Gradient Theory ◽  
Gradient Theory ◽  
Length Scale ◽  
Governing Equations ◽  
Scale Parameters ◽  
Material Length Scale ◽  
Material Length

In this study, the strain gradient theory is employed to derive governing equations of motion of a functionally graded Timoshenko’s sandwich microbeam resting on Pasternak’s foundation. The microbeam is including a micro-core and two piezoelectric face-sheets on top and bottom. The plate is actuated with applied electric potential at top of piezoelectric face-sheets. The governing equations of motion are derived using Hamilton’s principle and strain gradient theory. After derivation of governing equations of motion, the problem is solved for three classes of analysis including wave propagation, free vibration and bending analysis. The numerical results are presented to reflect the effect of important parameters such as wave number, applied voltage, inhomogeneous index, parameters of foundation and material length-scale parameters on the different responses. The obtained results indicated that changing material length-scale parameters leads to a stiffer structure that increase natural frequencies and decreases transverse deflection and maximum electric potential.

Application of an Element-free Galerkin Method to Water Wave Propagation Problems

2014 ◽  
Vol 60 (1-4) ◽  
pp. 87-105 ◽  
Author(s):  
Ryszard Staroszczyk
Keyword(s):  
Wave Propagation ◽  
Galerkin Method ◽  
Present Model ◽  
Free Surface Elevation ◽  
Element Free Galerkin Method ◽  
Plane Flow ◽  
Element Free Galerkin ◽  
Proposed Model ◽  
Sloping Bed ◽  
Element Free

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.

Wave propagation dynamics in a fractional Zener model with stochastic excitation

2020 ◽  
Vol 23 (6) ◽  
pp. 1570-1604
Author(s):  
Teodor Atanacković ◽  
Stevan Pilipović ◽  
Dora Seleši
Keyword(s):  
Wave Propagation ◽  
Constitutive Equation ◽  
Equations Of Motion ◽  
Weak Form ◽  
Stochastic Excitation ◽  
Expansion Theorem ◽  
Zener Model ◽  
Dissipation Inequality ◽  
Regularity Properties ◽  
Fractional Zener Model

Abstract Equations of motion for a Zener model describing a viscoelastic rod are investigated and conditions ensuring the existence, uniqueness and regularity properties of solutions are obtained. Restrictions on the coefficients in the constitutive equation are determined by a weak form of the dissipation inequality. Various stochastic processes related to the Karhunen-Loéve expansion theorem are presented as a model for random perturbances. Results show that displacement disturbances propagate with an infinite speed. Some corrections of already published results for a non-stochastic model are also provided.

Simulation of Engine Vibration on Nonlinear Hydraulic Engine Mounts

2005 ◽  
Author(s):  
A. R. Ohadi ◽  
G. Maghsoodi
Keyword(s):  
Equations Of Motion ◽  
Low Frequency ◽  
Governing Equations ◽  
Engine Mounts ◽  
Engine Vibration ◽  
Engine Mount ◽  
Rotational Motions ◽  
The Time Domain ◽  
Nonlinear Equations Of Motion ◽  
Four Cylinders

In this paper, vibration behavior of engine on nonlinear hydraulic engine mount including inertia track and decoupler is studied. In this regard, after introducing the nonlinear factors of this mount (i.e. inertia and decoupler resistances in turbulent region), the vibration governing equations of engine on one hydraulic engine mount are solved and the effect of nonlinearity is investigated. In order to have a comparison between rubber and hydraulic engine mounts, a 6 degree of freedom four cylinders V-shaped engine under inertia and balancing masses forces and torques is considered. By solving the time domain nonlinear equations of motion of engine on three inclined mounts, translational and rotational motions of engines body are obtained for different engine speeds. Transmitted base forces are also determined for both types of engine mount. Comparison of rubber and hydraulic mounts indicates the efficiency of hydraulic one in low frequency region.

A Numerical Model of In-Channel Pebble Bed Thermal Storage for a Solar Chimney

2012 ◽  
Author(s):  
Brandon Schulte ◽  
O. A. Plumb
Keyword(s):  
Numerical Model ◽  
Present Model ◽  
Thermal Storage ◽  
Implicit Time ◽  
Heat Transfer Characteristics ◽  
Solar Chimney ◽  
Pebble Bed ◽  
One Dimensional ◽  
Time Stepping ◽  
Daily Energy

In this study, solar chimney performance is numerically modeled. Previously published models have considered water bags and natural earth as means to store daytime thermal energy for nighttime operation of the system. The present model considers in-channel pebble bed thermal storage. A one-dimensional, implicit time stepping numerical model is developed to predict solar chimney performance throughout a 24 hour period. The model is partially verified with available experimental data. The daily energy, daily efficiency and heat transfer characteristics of the solar chimney with pebble bed thermal storage are summarized. The numerical simulation showed that by introducing a pebble bed, nightly exit velocities reach 40% of the peak daytime velocity. However, the daily kinetic energy delivered by a solar chimney with pebble bed thermal storage is much less than a traditional solar chimney, suggesting pebble bed thermal storage is more practicable in building heating applications as opposed to power generation.

Sign in / Sign up

Export Citation Format

Share Document