bluuebunny/crossref_metadata_2025_split huggingface dataset:
Equivalent Theodorsen Function for Fluidelastic Excitation in a Normal Triangular Array
Authors: Alyaldin Loay , Mureithi Njuki W. 
Published: March 2022

Abstract
Fluidelastic instability (FEI) remains the most important mechanism of flow-induced vibrations that can potentially cause large amplitude vibrations and early failure of nuclear steam generator tubes. In the present work, experimental tests are conducted to measure the unsteady and quasi-steady fluid forces acting on a normal triangular tube array of P/D=1.5 subjected to single-phase (water) cross-flow. The quasi-steady forces together with unsteady fluid forces are then used to estimate the time delay between the central tube motion and fluid forces on the tube itself. The time delay effect for the quasi-steady fluidelastic instability model is derived in the frequency domain in the form of an Equivalent Theodorsen Function. The results are compared to the first Equivalent Theodorsen function developed for rotated triangular array by Li and Mureithi [1]. Using the Equivalent Theodorsen Function, a stability analysis is carried out to predict the critical velocity for fluidelastic instability in a normal triangular array subjected to single-phase flow. The predicted stability threshold is consistent with previous published experimental data. The results show that the normal triangular array is more stable than the rotated triangular array.
Extravascular Cooling of Blood Using a Concentrated Thermoelectric Cooling Probe
Authors: Lee Connie Y. , Crouch A. Colleen , Jha Aman K. , Adapa Arjun R. , Diaz Jose A. , Pandey Aditya S. , Greve Joan M. , Pipe Kevin P. 
Published: March 2022

Abstract
Thermal therapies have strong potential for improving outcomes for patients suffering from cardiac arrest, neonatal hypoxic-ischemic encephalopathy, or medically refractory intracranial hypertension. We propose a novel tool to manipulate blood temperature through extravascular thermoelectric heat exchange of blood vessel walls and flowing blood. This tool is a concentrated cooling probe with several thermoelectric units combined to focus cooling at the application site. Using this tool, we aim to achieve desired levels of temperature control and potentially reduce complications associated with traditional intravascular or systemic thermal therapies. Leveraging the feedback control, speed, and reversible operation of thermoelectric cooling modules, the device can adapt to cool or heat as desired. Preclinical testing on rodent models confirmed rapid, significant reduction of intravenous jugular blood temperature when a prototype device was brought in contact with the left carotid artery (change in blood temperature of −4.74 ± 2.9 °C/h and −4.29 ± 1.64 °C/h for 0 °C and −5 °C cooling trials, respectively). Declines in rectal temperature were also noted, but at lesser magnitudes than for jugular blood (0 °C: −3.09 ± 1.29 °C/h; −5 °C: −2.04 ± 1.08 °C/h), indicating proof-of-concept of thermoelectric extravascular blood cooling within a relatively localized region of the body. With further improvements in the technique, there is potential for selective organ cooling via a reduction in the temperature of flowing blood.
The Effect of Multiple Coexisting Convective Modes in Determining Thermoacoustic Behavior of a Partially Premixed Swirl Flame
Authors: Sreedeep Sharan , Ramanan Vikram , Chakraborty Aritra , Chakravarthy Satyanarayanan R. 
Published: March 2022

Abstract
This study focuses on the effect of multiple heat release mode interactions on the amplitude of unsteady pressure oscillation for a partially premixed radial swirl burner, which uses methane as fuel. A range of operating conditions based on inlet airflow rate and global equivalence ratio is considered for this purpose. The pressure time series shows amplitude modulation at the dominant frequency for all the flow rates and equivalence ratios considered. Wavelet analysis based on continuous wavelet transform illustrates the presence of heat release rate fluctuations at multiple frequencies other than the dominant mode of pressure oscillation, with this more pronounced at low frequencies. Spectral proper orthogonal decomposition performed on time-resolved CH* chemiluminescence images reveal four dominant spatial modes of chemiluminescence, chosen based on the dominant wavelet coefficients for the same. The identified frequencies correspond to the duct-acoustic mode, helical mode (spectrally close to acoustic mode), low-frequency axisymmetric mode and low-frequency helical mode. The low-frequency helical mode (considered as the result of nonlinear interaction between acoustic and helical mode) and the low-frequency axisymmetric mode (considered to have independent existence) have similar spectral content. Amplitude modulation of unsteady pressure is found to be a result of the superposition of duct-acoustic mode and low-frequency axisymmetric mode, whereas reduction in overall pressure amplitude with the decrease in global equivalence ratio is seen to be a result of an increase in the dominance of low-frequency helical mode. The relative dominance of low-frequency helical mode over dominant pressure mode reduces the overall pressure amplitude.
Design for Life-Cycle Manufacture
Authors: Stoll Henry W. 
Published: March 2022

Abstract
As manufacturing companies become more comfortable with the design for manufacture (DFM) philosophy and more experienced in its practice, new opportunities for good design become possible. This paper presents a systematic, easy to use, methodology for applying the DFM philosophy at all stages of the engineering design process. Called design for life-cycle manufacture (DFLC), the approach focuses on three important considerations: (1) the physical concept, (2) the part decomposition, and (3) total product quality. The concept of total product quality is operationalized by decomposing it into three underlying components: quality of concept, quality of design, and quality of ownership. Each of these qualities is the focus of a particular step in the design for life-cycle manufacture methodology.
Shortening Production Cycle Times Through Setup Reductions and Quality Level Improvements
Authors: Diaby Moustapha 
Published: March 2022

Abstract
This paper addresses the issue of investing in reduced setup times and defect rates for a manufacturer of several products operating in a JIT environment. Demand for each product occurs at a constant rate. Production cycle times can be shortened by investing in setup time and defect rate reductions, respectively. The problem is to determine optimal levels of setup time reduction, defect rate reduction, and production cycle time for each product, subject to demand, process improvement budget, and manufacturing and warehousing capacity constraints, respectively. A general nonlinear optimization model of this problem is formulated. A convex geometric programming approximation of the model is developed in order to solve it. The approximation can be made to any desired degree of accuracy.
A Cost Model of New Electronic Products for Use During the Design and Development Phases
Authors: Shina Sammy G. , Saigal Anil 
Published: March 2022

Abstract
This paper outlines a methodology for developing a production cost model during the design phase of new electronic products. The model incorporates the analysis of the major steps required in the design and manufacturing process and the tradeoffs in specifying their capabilities. Several elements of traditional costing techniques such as activity based costing, capital equipment and manufacturing simulation are incorporated in this model. They are combined with quality measurement and improvement techniques such as the process capability index resulting in a comprehensive cost methodology that is sensitive to design quality, manufacturing yields and potential product volume.
Environmentally Conscious Design and Manufacturing: Concepts, Applications, and Perspectives
Authors: Zhang Hong C. , Kuo Tsai C. 
Published: March 2022

Abstract
Environmentally conscious design and manufacturing (ECD&M) is a view of manufacturing which includes the social and technological aspects of the design, synthesis, processing, and use of products in continuous or discrete manufacturing industries. The benefits of ECD&M include safer and cleaner factories, worker protection, reduced future costs for disposal, reduced environment and health risks, improved product quality at lower cost, better public image, and higher productivity. Environmentally conscious technologies and design practices will allow manufacturers to minimize waste and to turn waste into a profitable product. This paper updates information about ECD&M, which will in turn provide some general information, guidelines and references for research and implementation. In the meantime, more clear definitions of related terms used in the ECD&M area are provided. A brief future trend is also provided at the end of this paper.
Safety Analysis for a High Pressure Cylinder of an Oilfield Truck-Mounted Compressor
Authors: Zhou Si-Zhu , Chen Jacob Jen-Gwo 
Published: March 2022

Abstract
Regarding the safety analysis of a cylinder, the normal method is to consider it as a simplified thick-wall cylinder. According to the formulation of stress, safety about the thick-wall cylinder, the risk point and maximum stress, the deformation of a cylinder can be calculated. This method neglects the complex structure of the cylinder (the hole in it and the change of the cross-section area). However, it is necessary to do an accurate safety analysis for a high pressure, limited space cylinder mounted on a truck.
The objective of this paper is to present and illustrate a three dimensional finite element analysis for the safety of the high pressure cylinder and of the truck-mounted compressor. First, the model of finite element analysis is set up; then, the structure is divided into elements; after that, the risk cross-section and maximum stress of the cylinder are obtained. The stress curves about risk cross-section of the cylinder are drawn. Based on the results of the finite element analysis, the safety evaluation of the design is presented and the measurement about improving the safety coefficient of the cylinder are described.
Simulation of the Incompressible Viscous Cross-Flow Around an Oscillating Circular Cylinder via the Random Vortex Method
Authors: Akbari M. H. , Price S. J. 
Published: March 2022

Abstract
The random vortex method has been used to simulate the laminar incompressible flow around a circular cylinder oscillating transversely to the flow. The vorticity in the flow is represented by a number of discrete point vortices, which are given random walks to simulate the effect of viscous diffusion. The vortices are created on the cylinder surface to satisfy the no-slip boundary condition, they are convected using an inviscid flow assumption, where the induced velocities on each of the point vortices is obtained using a vortex-in-cell method. Using a time marching algorithim based on the above procedure, the flow around stationary and oscillating circular cylinders is investigated. In particular, the effect of frequency and magnitude of the forced oscillation on the dynamic force coefficients is considered. The results obtained are compared with other numerical solutions and with available experimental data. In general, both the qualitative and quantitative agreement between the present numerical simulation and other numerical results and experiments is good.
Vortex Structures in Flow Over a Rectangular Plate
Authors: Sheridan John , Hourigan Kerry , Mills Richard 
Published: March 2022

Abstract
Vortex shedding behind plates with rectangular trailing edges and both aerofoil and rectangular leading edges was investigated in a water tunnel. Previous studies, such as that presented by Mills et al. (1995), have shown that the base pressure, and hence drag, of such plates can be significantly altered by applying transverse perturbations at certain frequencies. Evidence has been presented to show that this is dependent on the interaction of shed vortices; this study is a first attempt to study the nature of the vortices and how they are influenced by the applied perturbation. This is done by using particle image velocimetry to measure the velocity field close to the plates. From these the vorticity field is derived and its response to perturbation examined. It is shown that the perturbation orders the vorticity field, resulting in increased peak vorticity and circulation in the shed vortices. Thus, their potential for inducing greater suction in the wake has been increased.
Vortex Induced Vibration of Chemical Plant Towers
Authors: Goyder H. G. D. 
Published: March 2022

Abstract
It is well known that vortex shedding can cause vibration of cylindrical structures. However, an actual case of vortex shedding from a chemical plant distillation column revealed that pipework on the outside of the column can cause the vibration to be significantly enhanced in comparison to that of a bare cylinder. This observation contradicts the commonly held view that equipment and pipework on the outside of cylinders reduces the effects of vortex shedding. Wind tunnel studies on a fully flexible sectional model of the column indicated that in some cases relatively small pipework can increase the vibration by a factor of three in comparison to the vibration of a plain cylinder. The case history, the wind tunnel studies and the solution adopted for the column are described in this paper.
Modeling Vortex-Excited Vibrations of Uniform Cylinders in Uniform and Shear Flow
Authors: Balasubramanian Sathish , Skop Richard A. 
Published: March 2022

Abstract
In recent years, nonlinear wake oscillator models have been shown to arise as a leading order approximation to the vortex shedding instability from a circular cylinder in a uniform flow (Alberéde and Monkewitz, 1992). Skop and Balasubramanian (1995) and Balasubramanian and Skop (1996) have extended the Van der Pol oscillator to model vortex shedding in non-uniform flow scenarios by introducing an axial diffusive coupling term in the equation. The results of their investigations have yielded a universal linear relationship between a turbulent kinematic viscosity that scales the diffusive coupling term and the shear parameter that quantifies the shear in the flow.
In this paper, following Skop and Balasubramanian (1997), we use the diffusively coupled Van der Pol oscillator as the governing equation for one component of the fluctuating lift force on the cylinder. The second component of the lift force is represented by a stall term which is linearly proportional to the transverse velocity of the cylinder. The coupled fluid-structural equations are employed to numerically simulate the response of a uniform pivoted cylinder in uniform and shear flow. The numerically predicted response amplitudes and bounds of lock-in are compared to available experimental results.
Failure Mechanism of a Thermocouple Well Caused by Flow-Induced Vibration: (1) — Numerical Simulation and Water Experiment of Flow-Induced Vibration
Authors: Yamaguchi Akira , Morishita Masaki , Wada Yusaku , Iwata Koji , Ichimiya Masakazu 
Published: March 2022

Abstract
In this paper, flow-induced vibration analysis and experiment of the thermocouple well sustained in cross flow of Japanese Fast Breeder Reactor Monju are performed. Navier-Stokes equations coupled with equations of structural motion are solved using the finite element method. The experiment is performed in water using real scale mock-up model. The in-line oscillation mode is simulated in both experiment and analysis and the results are consistent each other. Also observed in both the experiment and analysis are the symmetric vortices that are generated at both lateral sides of the cylinder in accordance with the cylinder natural frequency. Furthermore, it has been found both in numerical simulation and experiment that the thermocouple well oscillates at decreased flow rate if the natural frequency of the thermocouple is reduced. Based on the analytical and experimental results, a displacement response diagram that relates the displacement and the reduced velocity is established.
Failure Mechanism of a Thermocouple Well Caused by Flow-Induced Vibration: (2) — Interaction Between Flow-Induced Vibration and Fatigue Crack Growth in a Thermocouple Well
Authors: Wada Yusaku , Morishita Masaki , Yamaguchi Akira , Iwata Koji , Ichimiya Masakazu 
Published: March 2022

Abstract
In the preceding paper a simplified master diagram on the relationship between a reduced velocity Vr (= V/fD) and a reduced displacement amplitude y/D is investigated for the in-line oscillation mode of thermocouple well. Based on this diagram, high cycle fatigue failure process of a thermo-couple well; crack initiation, crack growth/arrest, and final stage of fracture, is evaluated in this paper.
The strain amplitude at the root between thin and thick well tubes can be analytically estimated considering the sharp notch effect, and the crack initiation life can be evaluated using a fatigue curve. After short crack growth the crack front line can move as a long crack. Both of natural frequency and damping constant are changed, and crack growth reduces the displacement amplitude. As the results crack arrest and delayed failure, which are peculiar in flow-induced vibration, can occur in a thermometer.
The Applicability of the Quasi-Steady Assumption for Two Staggered Circular Cylinders in Cross-Flow
Authors: Ting D. S.-K. , Wang D. J. , Price S. J. , Païdoussis M. P. 
Published: March 2022

Abstract
The applicability of the quasi-steady assumption for two staggered circular cylinders of equal diameter in cross-flow has been tested for ten geometrical arrangements, for Reynolds number (based on cylinder diameter and free-stream velocity) 4 × 104 ≤ Re ≤ 2 × 105, and reduced flow velocity 15 ≤ U/fD ≤ 300. With one cylinder stationary, the other one is forced to oscillate transversely to the flow with a half peak-to-peak amplitude / cylinder diameter ratio of 0.043, 0.047 or 0.17. The dynamic forces are deduced either from measured pressure distributions, or from direct force measurements on the cylinder, and these measurements are post-processed in the time and frequency domains, respectively. The applicability of the quasi-steady assumption is found to be strongly dependent on the relative positions of the two cylinders, in addition to U/fD. When the cylinder is in a sensitive flow region, where the spatial gradients of the static force coefficients are high, the quasi-steady assumption may not be applicable even for U/fD = 250. Away from the sensitive flow regions, the quasi-steady assumption is usually applicable for U/fD ≥ 50. In general, the fluidelastic forces depart rapidly from predictions based on the quasi-steady assumption with decreasing U/fD below the critical value.
Experiments on Vortex-Induced Vibrations of Pivoted Circular Cylinders
Authors: Szewczyk Albin A. , Balasubramanian Sathish , Haan Fred L. , Skop Richard A. 
Published: March 2022

Abstract
An experimental study of the vortex-induced vibrations of a pivoted circular cylinder was conducted to investigate the regions of lock-in between the vortex shedding and body vibration frequency for uniform and shear flow in Reynolds number ranges from 16,500 to 22,000. A rigid circular cylinder pivoted at the top by a bearing and stiffened by two transverse springs at the bottom was mounted in a wind tunnel. The cylinder was allowed to oscillate only in the cross-flow direction. The lock-in region was approached by varying the flow velocity. Measurements were made of the width of the frequency lock-in range, response amplitude, displacement time series and power spectral densities of the wake shedding for different Re numbers.
Vortex Shedding From a Rotary Oscillating Cylinder
Authors: Fujisawa N. , Ikemoto K. , Nagaya K. 
Published: March 2022

Abstract
Vortex shedding resonance of a circular cylinder wake to a forced rotational oscillation has been investigated experimentally by measuring the velocity fluctuations in the wake, pressure distributions over the cylinder surface, and visualizing the flow field with respect to cylinder oscillations. The vortex shedding resonance occurs near the natural shedding frequency at small-amplitude of cylinder oscillations, while the peak resonance frequency shifts to a lower one with an increase in oscillation amplitude. The estimated drag and lift forces acting on the cylinder indicate that the phase lag of fluid forces to the cylinder oscillations increases with an increase in oscillation amplitude, supporting the change of resonance frequency with oscillation amplitude. The comparative study of the measured pressure distributions and the simultaneous flow visualizations with respect to cylinder rotation shows the mechanisms of phase lag, which is due to the strengthened vortex formation and the modification of the surface pressure distributions.
Simulation of the Behavior of a Catamaran in Large Amplitude Motions
Authors: Tessier J. B. , Peseux B. , Delhommeau G. 
Published: March 2022

Abstract
A numerical model has been developed to study the large-amplitude motions of a catamaran subjected to severe wave conditions. In this paper, emphasis is placed on the description of the theoretical aspects. The nonlinear equations of motion concerning the rigid hulls and flexible beams are developed, including large rotations between bodies. The fluid-structure interaction model satisfies exactly the body boundary condition on the instantaneous surface of the moving body, defined as the part under the incident wave profile, while the free surface boundary conditions are linearized. The problem is solved using a transient free-surface Green function singularity distribution method.
The simulation of a nonlinear global behavior of a catamaran in following waves has been obtained and it illustrates the importance of nonlinear effects associated with the changing wetted hull.
A Low-Dimensional Model for Vortex Shedding Patterns Behind Vibrating Flexible Cables
Authors: Olinger D. J. 
Published: March 2022

Abstract
A recent focus in studies of vortex shedding behind circular cylinders has been the use of low-dimensional dynamical systems to predict wake dynamics. Use of purely temporal models has been limited by their inability to describe three-dimensional spatial flow variations along the cylinder span; a hallmark of transitional flows such as the cylinder wake. In the present work this limitation is overcome by developing a spatial-temporal map lattice utilizing a series of coupled circle map oscillators along the cylinder span. This model allows for study of vortex shedding patterns and wake dynamics behind vibrating flexible cables with prescribed frequency, amplitude, and mode shape. Standing wave mode shapes and traveling waves along the cable span are modeled. Lace-like vortex patterns are observed for the standing wave case. For traveling waves oblique shedding patterns are confirmed. Non-harmonic forcing outside the classical lock-on region yields vortex dislocation patterns in the wake.