Supporting New Insight in Pipeline Hydrodynamics Using Stochastic Approaches on External Corrosion Damage

2010 ◽  
Author(s):  
Zahiraniza Mustaffa ◽  
Pieter van Gelder
Keyword(s):  
Field Data ◽  
Corrosion Damage ◽  
Circular Cylinders ◽  
Fluid Structure Interactions ◽  
Fluid Structure ◽  
Subsea Pipeline ◽  
Structure Interaction ◽  
Actual Field ◽  
External Flows ◽  
External Corrosion

Several recent discoveries in the fluid-structure interactions between the external flows and circular cylinders placed close to the wall have added new values to the hydrodynamics of unburied marine pipelines on a seabed. The hydrodynamics of waves and/or currents introduced vortex flows surrounding the pipeline. External corrosions formed in marine pipelines were assumed to be partly contributed by such fluid-structure interactions. The spatial consequences of such interactions were of interest of this study. This paper summarized some experimental and numerical works carried out by previous researchers on these new discoveries. Actual field data were utilized in this study to support this hypothesis. The characteristics of corrosion orientations in the pipelines were studied comprehensively using stochastic approaches and results were discussed. Results adopted from the field data acknowledged well to the hypothesis from the reported literature. The updated knowledge from this fluid-structure interaction is hoped to be given more attention by the industry and perhaps to be incorporated into the current subsea pipeline designs.

Fluid-structure Interactions

1998 ◽  
Vol 120 (04) ◽  
pp. 66-68 ◽  
Author(s):  
Klaus-Ju¨rgen Bathe
Keyword(s):  
Finite Element ◽  
Fluid Structure Interactions ◽  
Physical Processes ◽  
Fluid Structure ◽  
Modeling And Analysis ◽  
Structure Interaction ◽  
Design And Manufacturing ◽  
Physical Phenomena ◽  
Acoustic Fluid ◽  
Made In

This article reviews finite element methods that are widely used in the analysis of solids and structures, and they provide great benefits in product design. In fact, with today’s highly competitive design and manufacturing markets, it is nearly impossible to ignore the advances that have been made in the computer analysis of structures without losing an edge in innovation and productivity. Various commercial finite-element programs are widely used and have proven to be indispensable in designing safer, more economical products. Applications of acoustic-fluid/structure interactions are found whenever the fluid can be modeled to be inviscid and to undergo only relatively small particle motions. The interplay between finite-element modeling and analysis with the recognition and understanding of new physical phenomena will advance the understanding of physical processes. This will lead to increasingly better simulations. Based on current technology and realistic expectations of further hardware and software developments, a tremendous future for fluid–structure interaction applications lies ahead.

Analysis of Fluid-Structure Interaction of an Elastic Blade in Cascade

2002 ◽  
Author(s):  
R. C. K. Leung ◽  
Y. L. Lau ◽  
R. M. C. Si
Keyword(s):  
Numerical Technique ◽  
Fluid Structure Interaction ◽  
Uniform Flow ◽  
Frequency Parameter ◽  
Generation Process ◽  
Noise Generation ◽  
Fluid Structure Interactions ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Normalized Frequency

A time-marching numerical model for the analysis of fluid-structure interaction caused by oncoming alternating vortices has been developed by Jadic et al. (1998). Its applicability to analyzing realistic fluid–structure interaction problems has successfully been established in a recent experimental work of a flat plate in a circular cylinder wake (Lau et al. 2002). Using the model, So et al. (1999) have predicted that, under the excitation of oncoming Karman vortex street (KVS) vortices, an elastic airfoil/blade in inviscid uniform flow exhibits two types of fluid–structure resonance, namely aerodynamic and structural resonance. Aerodynamic resonance is of pure aerodynamic origin and occurs with rigid airfoil/blade excited at normalized frequency parameter c/d = 0.5, 1.5, 2.5 etc., where c is the blade chord and d is the streamwise separation between two neighboring vortices. For an elastic airfoil/blade, as a result of coupled fluid–structure interaction, structural resonance occurs at a normalized frequency close to the natural frequency in vacuo of the airfoil/blade. The occurrence of fluid-structure resonance has also been shown critical in noise generation process (Leung & So 2001). The present study extends the scope of the analysis to fluid–structure interactions occurring in axial–flow turbomachine cascade. When the flow is passing through the rotor, it generates wakes containing KVS vortices behind the rotor blades. The convecting wake will induce perturbations on the downstream stator blades at a wake passing frequency (Rao 1991). Such wake–blade interaction is important in determining the fatigue life of the blades and noise generation of the cascade. The cascade analysis starts with modeling the two-dimensional turbine stator by five high–loading blades evenly separated by s in inviscid uniform flow. Oncoming KVS vortices are released upstream to represent the passing wake originating from the rotor, and are allowed to pass through the stator blades. The blade pitch to blade chord ratio s/c and normalized frequency parameter c/d are important parameters of the problems. Fluid–structure interactions are fully resolved by the same numerical technique (Jadic et al. 1998, So et al. 1999). The combined effects of s/c and c/d on the aerodynamic and structural responses of the central blade are studied and discussed.

Investigations on the Fluid-Structure Interactions of Fishing Nets

2006 ◽  
Author(s):  
Hans-Joachim Winkel ◽  
Mathias Paschen
Keyword(s):  
Theoretical Models ◽  
Transverse Force ◽  
Circular Cylinders ◽  
Fluid Structure Interactions ◽  
Calculation Methods ◽  
Fluid Structure ◽  
Long Time ◽  
Helical Strakes

Modern nets consist of meshes made of threads or twines with spirals or helical strakes. Fluid-structure interactions have been investigated in Rostock for a long time applying different theoretical models. Because of great net flexibility there is a need of calculation methods which consider the main physical qualities. This is done by the approximation of wake of threads by results from circular cylinders and influence of circulation, which is known from measurements of transverse force. Results of measurements with two models with and without spirals are given for comparison.

Fluid Structure Interactions for Blast Wave Mitigation

2011 ◽  
Vol 78 (3) ◽  
Author(s):  
Wen Peng ◽  
Zhaoyan Zhang ◽  
George Gogos ◽  
George Gazonas
Keyword(s):  
Shock Wave ◽  
Blast Wave ◽  
Fluid Structure Interaction ◽  
Wave Formation ◽  
Plate Motion ◽  
Fluid Structure Interactions ◽  
Free Standing ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Shock Wave Formation

The dynamic response of a free-standing plate subjected to a blast wave is studied numerically to investigate the effects of fluid-structure interaction (FSI) in blast wave mitigation. Previous work on the FSI between a blast wave and a free-standing plate (Kambouchev, N., et al., 2006, “Nonlinear Compressibility Effects in Fluid-Structure Interaction and Their Implications on the Air-Blast Loading of Structures,” J. Appl. Phys., 100(6), p. 063519) has assumed a constant atmospheric pressure at the back of the plate and neglected the resistance caused by the shock wave formation due to the receding motion of the plate. This paper develops an FSI model that includes the resistance caused by the shock wave formation at the back of the plate. The numerical results show that the resistance to the plate motion is especially pronounced for a light plate, and as a result, the previous work overpredicts the mitigation effects of FSI. Therefore, the effects of the interaction between the plate and the shock wave formation at the back of the plate should be considered in blast wave mitigation.

Cerebrospinal Fluid-Structure Interactions: The Development of Mathematical Models Accessible to Clinicians

2014 ◽  
Author(s):  
Novak S. J. Elliott
Keyword(s):  
Cerebrospinal Fluid ◽  
Mathematical Models ◽  
Clinical Application ◽  
Fluid Structure Interaction ◽  
Pressure Vessels ◽  
Fluid Structure Interactions ◽  
Research Methodologies ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Perceived Complexity

Physical scientists work with clinicians on biomechanical problems, yet the predictive capabilities of mathematical models often remain elusive to clinical collaborators. This is due to both conceptual differences in the research methodologies of each discipline, and the perceived complexity of even simple models. This limits expert medical input, affecting the applicability of the results. Moreover, a lack of understanding undermines the medical practitioner’s confidence in modeling predictions, hampering its clinical application. In this paper we consider the disease syringomyelia, which involves the fluid-structure interaction of pressure vessels and pipes, as a paradigm of the nexus between the modeling approaches of physical scientists and clinicians. The observations made are broadly applicable to cross-disciplinary research between engineers and non-technical specialists, such as may occur in academic-industrial collaborations.

On the Mechanics of Phonation and Fluid-Structure Interactions in a Three Dimensional Vocal Fold Model

2007 ◽  
Author(s):  
Somesh Khandelwal ◽  
Thomas Siegmund ◽  
Steve H. Frankel
Keyword(s):  
Vibration Amplitude ◽  
Vocal Fold ◽  
Flow Model ◽  
Three Dimensional ◽  
The Self ◽  
Elastic Response ◽  
Fluid Structure Interactions ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Laminar Flow Model

It is hypothesized that the characteristics of vocal fold self oscillation is dependent on the nonlinearity of the solid structure i.e. the tissue. Studies of fluid structure interaction are conducted for three dimensional larynx models. Simulations were performed using the codes FLUENT and ABAQUS coupled by the code MpCCI. For the air an unsteady, laminar flow model was considered. Visco-hyperelasticity was used to characterize the solid domain representing the tissue structure. The computational model is used to conduct a parametric study on the self-oscillation response of the model with focus on the influence of the non-linearity in the hyperelastic response. Individual computations were compared by documenting the variation of the total energy of the structure. It is demonstrated that dissipation in the flow as well as the non-linearity in the elastic response all interact to stabilize or destabilize the vibration amplitude.

Nanoscale Fluid-Structure Interactions in Cytoplasm During Freezing

2012 ◽  
Author(s):  
Altug Ozcelikkale ◽  
Bumsoo Han
Keyword(s):  
Theoretical Model ◽  
Physical Properties ◽  
Spatial Heterogeneity ◽  
Fluid Structure Interaction ◽  
Fluid Structure Interactions ◽  
Spatial Homogeneity ◽  
Intracellular Space ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Poroelastic Material

In this study, a theoretical model is developed to simulate the biophysical events in the intracellular spaces considering the biphasic, i.e., poroelastic, behavior of the cytoplasm. Most previous studies in the cryobiology literature have modeled the biophysical response of cells to freezing assuming the spatial homogeneity of all physical properties within the intracellular space without considering fluid-structure interaction in both the intracellular and extracellular spaces. However, a few recent studies strongly indicate that spatial heterogeneity in the intracellular space occurs during freezing. We thus model the cytoplasm as a poroelastic material considering nanoscale fluid-structure interaction between the cytoskeleton and cytosol, and the effects of hierarchical fluid-structure interaction across the cell during freezing.

Fluid Structure Interaction Problems in Turbomachinery Using RBF Interpolation and Greedy Algorithm

2014 ◽  
Author(s):  
Yannick Rozenberg ◽  
Stéphane Aubert ◽  
Guillaume Bénéfice
Keyword(s):  
Greedy Algorithm ◽  
Periodic Boundary ◽  
Periodic Boundary Conditions ◽  
Basis Functions ◽  
Control Points ◽  
Powerful Method ◽  
Fluid Structure Interactions ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Constant Pitch

In an effort to provide accurate simulations of fluid-structure interactions in turbomachinery, this paper describes a powerful method to deform mesh, using interpolation based on radial basis functions (RBF). It has been assessed on a 3D annular turbine, including a tip gap. The main difficulty of this method is to define number and position of control points. A greedy algorithm is proposed to address this issue and is tested on the annular turbine and a deforming panel placed in a shock tube. Finally, the method is slightly adapted to take into account periodic boundary conditions, which allow mesh morphing for a unique interblade channel by preserving constant pitch on lateral boundaries.

scholarly journals Numerical Methods for Fluid-Structure Interaction — A Review

2012 ◽  
Vol 12 (2) ◽  
pp. 337-377 ◽  
Author(s):  
Gene Hou ◽  
Jin Wang ◽  
Anita Layton
Keyword(s):  
Numerical Methods ◽  
Fluid Structure Interaction ◽  
Fluid Flows ◽  
Fluid Structure Interactions ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Wide Range ◽  
Recent Developments ◽  
Conforming Meshes ◽  
Incompressible Fluid Flows

AbstractThe interactions between incompressible fluid flows and immersed structures are nonlinear multi-physics phenomena that have applications to a wide range of scientific and engineering disciplines. In this article, we review representative numerical methods based on conforming and non-conforming meshes that are currently available for computing fluid-structure interaction problems, with an emphasis on some of the recent developments in the field. A goal is to categorize the selected methods and assess their accuracy and efficiency. We discuss challenges faced by researchers in this field, and we emphasize the importance of interdisciplinary effort for advancing the study in fluid-structure interactions.

scholarly journals Frequency domain approach to decay rates for a coupled hyperbolic-parabolic system

2021 ◽  
Vol 0 (0) ◽  
pp. 0
Author(s):  
Bopeng Rao ◽  
Xu Zhang
Keyword(s):  
Asymptotic Behavior ◽  
Wave Equation ◽  
Heat Equation ◽  
Frequency Domain ◽  
Parabolic System ◽  
Decay Rates ◽  
Fluid Structure Interactions ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Frequency Domain Approach

<p style='text-indent:20px;'>We consider the asymptotic behavior of a linear model arising in fluid-structure interactions. The system is formed by a heat equation and a wave equation in two distinct domains, which are coupled by atransmission condition along the interface of the domains. By means of the frequency domain approach, we establish some decay rates for the whole system. Our results also showthat the decay of the fluid-structure interaction depends not only on the transmission of the damping from the heat equation to the wave equation, but also on the location of the damping for the wave equation.</p>

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