scholarly journals Influence of shear effects on the characteristics of axisymmetric wave propagation in a buried fluid-filled pipe

2020 ◽  
Author(s):  
Ping Lu ◽  
Xiaozhen Sheng ◽  
Yan Gao ◽  
Ruichen Wang
Keyword(s):  
Wave Propagation ◽  
Pipe Wall ◽  
Surrounding Medium ◽  
Three Dimensional ◽  
Engineering Application ◽  
Leak Detection ◽  
Calculation Model ◽  
Theoretical Research ◽  
Axisymmetric Wave ◽  
Shear Effects

Abstract The acoustic propagation characteristics of axisymmetric waves have been widely used in leak detection of fluid-filled pipes. The related acoustic methods and equipment are gradually coming to the market, but their theoretical research obviously lags behind the field practice, which seriously restricts the breakthrough and innovation of this technology. Based on the fully three-dimensional effect of the surrounding medium, a coupled motion equation of axisymmetric wave of buried liquid-filled pipes is derived in detail, a contact coefficient is used to express the coupling strength between surrounding medium and pipe, then, a general equation of motion was derived which contain the pipe soil lubrication contact, pipe soil compact contact and pipe in water and air. Finally, the corresponding numerical calculation model is established and solved used numerical method. The shear effects of the surrounding medium and the shear effects at the interface between surrounding medium and pipe are discussed in detail. The output indicates that the surrounding medium is to add mass to the pipe wall, but the shear effect is to add stiffness. With the consideration of the contact strength between the pipe and the medium, the additional mass and the pipe wall will resonate at a specific frequency, resulting in a significant increase in the radiation wave to the surrounding medium. The research contents have great guiding effect on the theory of acoustic wave propagation and the engineering application of leak detection technology in the buried pipe.

scholarly journals Influence of shear effects on the characteristics of axisymmetric wave propagation in a buried fluid-filled pipe

2020 ◽  
Author(s):  
Ping Lu ◽  
Xiaozhen Sheng ◽  
Yan Gao ◽  
Ruichen Wang
Keyword(s):  
Wave Propagation ◽  
Pipe Wall ◽  
Surrounding Medium ◽  
Three Dimensional ◽  
Engineering Application ◽  
Leak Detection ◽  
Calculation Model ◽  
Theoretical Research ◽  
Axisymmetric Wave ◽  
Shear Effects

Abstract The acoustic propagation characteristics of axisymmetric waves have been widely used in leak detection of liquid-filled pipes. The related acoustic methods and equipment are gradually coming to the market, but their theoretical research obviously lags behind the field practice, which seriously restricts the breakthrough and innovation of this technology. Based on the fully three-dimensional effect of the surrounding medium, a coupled motion equation of axisymmetric wave of buried liquid-filled pipes is derived in detail, a contact coefficient is used to express the coupling strength between surrounding medium and pipe, then, a general equation of motion was derived which contain the pipe soil lubrication contact, pipe soil co mpact contact and pipe in water and air. Finally, the corresponding numerical calculation model is established and solved used numerical method. The shear effects of the surrounding medium and the shear effects at the interface between surrounding medium and pipe are discussed in detail. The output indicates that the surrounding medium is to add mass to the pipe wall, but the shear effect is to add stiffness. With the consideration of the contact strength between the pipe and the medium, the additional mass and the pipe wall will resonate at a specific frequency, resulting in a significant increase in the radiation wave to the surrounding medium. The research contents have great guiding effect on the theory of acoustic wave propagation and the engineering application of leak detection technology in the buried pipe.

Simulation on Torpedo Unsteady Hydrodynamic with the Movement in the Longitudinal Plane

2013 ◽  
Vol 791-793 ◽  
pp. 1073-1076
Author(s):  
Ming Yang ◽  
Shi Ping Zhao ◽  
Han Ping Wang ◽  
Lin Peng Wang ◽  
Shao Zhu Wang
Keyword(s):  
Three Dimensional ◽  
Engineering Application ◽  
Calculation Model ◽  
Trajectory Design ◽  
Design Calculation ◽  
Variable Speed ◽  
Accurate Calculation ◽  
Longitudinal Plane ◽  
Submerged Body ◽  
Mesh Method

The unsteady hydrodynamic accurate calculation is the premise of submerged body trajectory design and maneuverability design. Calculation model of submerged body unsteady hydrodynamic with the movement in the longitudinal plane was established, which based on unsteady three-dimensional incompressible fluid dynamics theory. Variable speed translational and variable angular velocity of the pitching motion in the longitudinal plane of submerged body was achieved by dynamic mesh method. The unsteady hydrodynamic could be obtained by model under the premise of good quality grid by the results. Modeling methods can learn from other similar problems, which has engineering application value.

On Some Particularities of the Axisymmetric Wave Propagation in the Initially Twisted Circular Compound Cylinders

2010 ◽  
Author(s):  
Surkay Akbarov ◽  
Mugan Guliev ◽  
Tamer Kepceler
Keyword(s):  
Wave Propagation ◽  
Solution Method ◽  
Mathematical Formulation ◽  
Three Dimensional ◽  
Body Model ◽  
Axisymmetric Wave ◽  
Piecewise Homogeneous Body ◽  
Linearized Theory ◽  
New Type ◽  
Circular Compound

This paper investigates some particularities related with the influence of the magnitude of the initial twisting of the axisymmetric wave propagation in the initially twisted circular bi-material compounded cylinder. The investigation is carried out within the scope of the piecewise homogeneous body model with the use of the three-dimensional linearized theory of elastic wave propagation in an initially stressed body. The mathematical formulation of the problem is presented and the corresponding solution method is proposed and developed. The numerical results are further presented and discussed. In particular, the mechanism of the arising of the new type modes caused by the initial twisting of the circular compounded cylinders is established.

Research on Tuned Mass Damper for Vibration Control of Tower under Multi-Dimensional Seismic Excitations

2013 ◽  
Vol 353-356 ◽  
pp. 2181-2186
Author(s):  
Yu Wei Dai ◽  
Chao Liu ◽  
Wen Feng Li ◽  
Li Tian
Keyword(s):  
Vibration Control ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Engineering Application ◽  
Element Model ◽  
Tuned Mass Damper ◽  
Calculation Model ◽  
Seismic Excitations ◽  
Mass Damper ◽  
Three Dimensional Finite Element

The tuned mass damper (TMD) for vibration control of tower subjected to multi-dimensional seismic excitations is studied in this paper. Calculation model of the tuned mass damper is introduced, and the equations of motion of a tower with tuned mass damper are derived, and the calculation parameters of the tuned mass damper are given based on the control structure. According to a practical engineering, the three-dimensional finite element model of a tower is established using SAP2000. Three typical seismic records are selected according the code of seismic design. Vibration control for tower model with tuned mass damper under multi-dimensional seismic excitations is performed by using numerical simulation. The maximum responses of displacement and axial force of the tower structure without and with TMD are obtained. The results show that the TMD could decrease the responses of the tower in three directions, and the tower with TMD can be a reference for tower practice engineering application.

Axisymmetric Wave Propagation in the Initially Twisted Circular Compound Cylinders

2009 ◽  
Author(s):  
Surkay Akbarov ◽  
Mugan Guliev
Keyword(s):  
Wave Propagation ◽  
Solution Method ◽  
Mathematical Formulation ◽  
Three Dimensional ◽  
Homogeneous Body ◽  
Body Model ◽  
Axisymmetric Wave ◽  
Piecewise Homogeneous Body ◽  
Linearized Theory ◽  
Circular Compound

Within the scope of the piecewise homogeneous body model with the use of the three-dimensional linearized theory of elastic wave propagation in an initially stressed body, the problem of the axisymmetric wave propagation in an initially twisted circular compound cylinders is studied. The mathematical formulation of the problem is presented and the corresponding solution method is proposed and developed, following which the numerical results are presented and discussed. In particular, it is established that as a result of the initial twisting of the circular compound cylinders, new axisymmetric wave modes arise.

Study of dynamic pressure on the packer for deep-water perforation

Open Physics ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 215-223
Author(s):  
Hao Huang ◽  
Qiao Deng ◽  
Hui Zhang
Keyword(s):  
Deep Water ◽  
Peak Pressure ◽  
Orthogonal Design ◽  
Dynamic Pressure ◽  
Three Dimensional ◽  
Calculation Model ◽  
Well Testing ◽  
Technical Problems ◽  
Wellbore Pressure ◽  
Three Dimensional Finite Element

Abstract The packer is one of the most important tools in deep-water perforation combined well testing, and its safety directly determines the success of perforation test operations. The study of dynamic perforating pressure on the packer is one of the key technical problems in the production of deep-water wells. However, there are few studies on the safety of packers with shock loads. In this article, the three-dimensional finite element models of downhole perforation have been established, and a series of numerical simulations are carried out by using orthogonal design. The relationship between the perforating peak pressure on the packer with the factors such as perforating charge quantity, wellbore pressure, perforating explosion volume, formation pressure, and elastic modulus is established. Meanwhile, the database is established based on the results of numerical simulation, and the calculation model of peak pressure on the packer during perforating is obtained by considering the reflection and transmission of shock waves on the packer. The results of this study have been applied in the field case of deep-water well, and the safety optimization program for deep-water downhole perforation safety has been put forward. This study provides important theoretical guidance for the safety of the packer during deep-water perforating.

scholarly journals Experimental and Numerical Investigation of 3D Dam-Break Wave Propagation in an Enclosed Domain with Dry and Wet Bottom

2021 ◽  
Vol 11 (12) ◽  
pp. 5638
Author(s):  
Selahattin Kocaman ◽  
Stefania Evangelista ◽  
Hasan Guzel ◽  
Kaan Dal ◽  
Ada Yilmaz ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Numerical Models ◽  
Three Dimensional ◽  
Dam Break ◽  
Dam Failure ◽  
Navier Stokes ◽  
Negative Wave ◽  
Through Flow ◽  
Instantaneous Removal ◽  
Surface Patterns

Dam-break flood waves represent a severe threat to people and properties located in downstream regions. Although dam failure has been among the main subjects investigated in academia, little effort has been made toward investigating wave propagation under the influence of tailwater depth. This work presents three-dimensional (3D) numerical simulations of laboratory experiments of dam-breaks with tailwater performed at the Laboratory of Hydraulics of Iskenderun Technical University, Turkey. The dam-break wave was generated by the instantaneous removal of a sluice gate positioned at the center of a transversal wall forming the reservoir. Specifically, in order to understand the influence of tailwater level on wave propagation, three tests were conducted under the conditions of dry and wet downstream bottom with two different tailwater depths, respectively. The present research analyzes the propagation of the positive and negative wave originated by the dam-break, as well as the wave reflection against the channel’s downstream closed boundary. Digital image processing was used to track water surface patterns, and ultrasonic sensors were positioned at five different locations along the channel in order to obtain water stage hydrographs. Laboratory measurements were compared against the numerical results obtained through FLOW-3D commercial software, solving the 3D Reynolds-Averaged Navier–Stokes (RANS) with the k-ε turbulence model for closure, and Shallow Water Equations (SWEs). The comparison achieved a reasonable agreement with both numerical models, although the RANS showed in general, as expected, a better performance.

Guided Surface Waves on an Elastic Half Space

1971 ◽  
Vol 38 (4) ◽  
pp. 899-905 ◽  
Author(s):  
L. B. Freund
Keyword(s):  
Wave Propagation ◽  
Surface Wave ◽  
Surface Waves ◽  
Half Space ◽  
Body Wave ◽  
Three Dimensional ◽  
Elastic Half Space ◽  
Normal Displacement ◽  
Rigid Barrier ◽  
Wave Disturbances

Three-dimensional wave propagation in an elastic half space is considered. The half space is traction free on half its boundary, while the remaining part of the boundary is free of shear traction and is constrained against normal displacement by a smooth, rigid barrier. A time-harmonic surface wave, traveling on the traction free part of the surface, is obliquely incident on the edge of the barrier. The amplitude and the phase of the resulting reflected surface wave are determined by means of Laplace transform methods and the Wiener-Hopf technique. Wave propagation in an elastic half space in contact with two rigid, smooth barriers is then considered. The barriers are arranged so that a strip on the surface of uniform width is traction free, which forms a wave guide for surface waves. Results of the surface wave reflection problem are then used to geometrically construct dispersion relations for the propagation of unattenuated guided surface waves in the guiding structure. The rate of decay of body wave disturbances, localized near the edges of the guide, is discussed.

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