The onset of flow-induced vibrations in a square tube array subjected to cross-flow
03 May 2010-pp 80-88
TL;DR: In this paper, the authors proposed a finite element approach to model the interaction between tubes in the bundle, which is represented by fluidelastic coupling forces, defined in terms of the multi-degree-of-freedom elastodynamic behavior of each tube.
Abstract: The need for accurate prediction of vibration and wear of heat exchangers in service has placed greater emphasis on improved modeling of the associated phenomenon of flow-induced vibrations. It was recognized that modeling of the complex dynamics of fluidelastic forces, that give rise to vibrations of tube bundles, requires a great deal of experimental insight. Accordingly, the prediction of the flow-induced vibration due to unsteady cross-flow can be greatly aided by semi-analytical models, in which some coefficients are determined experimentally. In this paper, the elastodynamic model of the tube array is formulated using the finite element approach, wherein each tube is modeled by a set of finite tube-elements. The interaction between tubes in the bundle is represented by fluidelastic coupling forces, which are defined in terms of the multi-degree-of-freedom elastodynamic behavior of each tube in the bundle. A laboratory test rig with an instrumented square bundle is constructed to measure the fluidelastic coefficients used to tune the developed dynamic model. The test rig admits two different test bundles; namely the inline-square and 45o rotated-square tube arrays. Measurements were conducted to identify the flow-induced dynamic coefficients. The developed scheme was utilized in predicting the onset of flow-induced vibrations, and results were examined in the light of TEMA predictions. The comparison demonstrated that TEMA guidelines are more conservative in the two configurations considered.
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01 Jun 1994
TL;DR: Once the motion-dependent fluid-force coefficients have been measured, a reliable design guideline can be developed for fluidelastic instability of tube arrays in crossflow based on the unsteady flow theory.
Abstract: Motion-dependent fluid forces acting on a tube array were measured as a function of excitation frequency, excitation amplitude, and flow velocity. Fluid-damping and fluid-stiffness coefficients were obtained from measured motion-dependent fluid forces as a function of reduced flow velocity and excitation amplitude. The water channel and test setup provide a sound facility for obtaining key coefficients for fluidelastic instability of tube arrays in crossflow. Once the motion-dependent fluid-force coefficients have been measured, a reliable design guideline, based on the unsteady flow theory, can be developed for fluidelastic instability of tube arrays in crossflow.
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10 May 1979TL;DR: The terminology, coordinate systems, and fundamental concepts of structural behavior are defined, laying the foundation for the study of more advanced treatments such as the finite element method.
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454 citations
TL;DR: A review of the state of the art of two classes of vibration problems encountered in reactors and reactor peripherals is presented in this paper, where a historical perspective is given, in which milestone contributions that have advanced the state-of-the-art are highlighted.
256 citations
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...Progress in research activities related to this problem was reviewed by Paidoussis [3], Price [4], and Weaver et al. [5]....
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...Progress in research activities related to this problem was reviewed by Paidoussis [3], Price [4], and Weaver et al....
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TL;DR: In this article, the critical velocities of cylinders supported by elastic spars were calculated by using the measured unsteady fluid dynamic forces, which are induced by the vibrating cylinders.
166 citations
"The onset of flow-induced vibration..." refers methods or result in this paper
...[17-19], introduced a method for calculating the critical flow velocity based on the unsteady flow theory....
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...Similar behavior was also observed by previous investigators [17], and was attributed to the possible contribution of the Karman vortex or similar vortices at lower velocities....
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TL;DR: For the nonlinear eigenvalue problem, the residual inverse iteration with variable shift is defined in this article, where the convergence rate is at least linear with convergence factor proportional to the variance of the residual.
Abstract: For the nonlinear eigenvalue problem $A(\hat \lambda )\hat x = 0$, where $A( \cdot )$ is a matrix-valued operator, residual inverse iteration with shift $\sigma $ is defined by \[ a^{(l + 1)} : = {\text{const. }}(x^{(l)} - A(\sigma )^{ - 1} A(\lambda _{l + 1} )x^{(l)} ),\] where $\lambda _{l + 1} $ is an appropriate approximation of $\hat \lambda $. In the linear case, $A(\lambda ) = A - \lambda I$, this is theoretically equivalent to ordinary inverse iteration, but the residual formulation results in a considerably higher limit accuracy when the residual $A(\lambda _{l + 1} )x^{(l)} = Ax^{(l)} - \lambda _{l + 1} x^{(l)} $ is accumulated in double precision. In the nonlinear case, if $\sigma $ is sufficiently close to $\hat \lambda $, convergence is at least linear with convergence factor proportional to $| {\sigma - \hat \lambda } |$. As with ordinary inverse iteration, the convergence can be accelerated by using variable shifts.
149 citations
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...Neumaier [27] presented an inverse iteration scheme for the nonlinear eigenvalue problem....
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TL;DR: In this paper, a brief overview of progress in understanding of flow-induced vibration in power and process plant components is provided along with suggestions for future research on unresolved issues, including turbulence, vorticity shedding, fluidelastic instability and axial flows.
Abstract: This paper provides a brief overview of progress in our understanding of flow-induced vibration in power and process plant components. The flow excitation mechanisms considered are turbulence, vorticity shedding, fluidelastic instability, axial flows, and two-phase flows. Numerous references are provided along with suggestions for future research on unresolved issues.
149 citations