Liquid-filled Tube Research Articles

In situ ground settlement sensor for oil-tank monitoring by combining a fiber-optic low-coherent interferometry with a fine mechanical design.

An in situ robust ground settlement (IR-GS) sensor was designed to meet the requirements for oil-tank health monitoring by combining a low-coherent fiber-optic interferometry with a fine mechanical spline shaft. A floating mirror was mounted on the shaft and moved up and down along with the liquid surface. The liquid-contained chambers were hydraulically connected at the bottom by using a liquid-filled tube. The liquid level inside each chamber was initially at equal level. One of the chambers was fixed on a steady ground point, which was chosen in a surveying point of view and served as a reference. The others were distributed around an oil tank and separated the tank's perimeter into eight equal spans. Thereby, the health states of the oil tank were able to be evaluated based on these sensing results. Interrogation of the sensor was employed via a low-coherent fiber-optic Michelson interferometer. One path of the interferometer was composed by the floating mirror, whereupon a light was reflected. The other path was projected to a mirror that was fixed on a stepping motor. Therefore, the corresponding liquid level could be optically surveyed. Differential settlements between each chamber and the reference served as a measure of how much the liquid level was changed from its initials. Experimental tests demonstrated that this IR-GS design, with the optimized shape and weights of the spline shaft, could overcome the error caused by dust, hysteresis, temperature, etc. and meet the practical requirement in the accuracy of ±0.5mm. A practical application was carried out, and its long-term stability has been proved.

Propulsion of a Magnetic Material-Applied Microrobot in a Tube Based on a Wireless Power Transfer System

Microrobots can be utilized in various applications, but their ability to move and perform tasks in various environments is especially important. In this paper, we introduce a 3-mm microrobot that can move in a liquid-filled tube, such as a vein, against gravity using an external wireless power transfer-based microrobot propulsion system. The force required to move against gravity was determined by calculating the effects of buoyance and gravity on the microrobot. Based on this information, the current required for the transmitting coil to induce sufficient propulsion was derived using the relation between the incident magnetic field and the magnetic force on a magnetic material. The propulsion system was experimentally tested, and the microrobot successfully moved upward against gravity. In addition, the level of human exposure to the applied electromagnetic field was determined to be within recommended guidelines using the electromagnetic simulation software Sim4Life.

Mechanics of Low-Temperature Phase Transition in Liquid-Filled Elastic Capillary Tube

Mechanics of Low-Temperature Phase Transition in Liquid-Filled Elastic Capillary Tube

Three-dimensional modeling of gas injection into a closed liquid-filled tube region

Three-dimensional modeling of air injection into a closed pipe region filled with liquid (water, liquid lead) is carried out at high pressure drops. It is shown that in the three-dimensional calculation, the instability of the interphase surface in the form of ring waves of deformation on the upper surface of the projectile is significantly manifested. When air is injected into water, the difference in the configuration of the interphase surface obtained in axisymmetric (two-dimensional) and three-dimensional calculations is insignificant. When injected into a liquid with a substantially higher density (liquid lead), this difference is especially pronounced in the compression phase of the gas projectile.

A simple experimental system to illustrate the nonlinear properties of a linear chain under compression

A linear chain of spheres confined by a transverse harmonic potential experiences localized buckling under compression. We present simple experiments using gas bubbles in a liquid-filled tube to demonstrate this phenomenon. Our findings are supported semi-quantitatively by numerical simulations. In particular, we demonstrate the existence of a critical value of compression for the onset of buckling.

Forced motion of a cylinder within a liquid-filled elastic tube – a model of minimally invasive medical procedures

This work analyses the viscous flow and elastic deformation created by the forced axial motion of a rigid cylinder within an elastic liquid-filled tube. The examined configuration is relevant to various minimally invasive medical procedures in which slender devices are inserted into fluid-filled biological vessels, such as vascular interventions, interventional radiology, endoscopies and laparoscopies. By applying the lubrication approximation, thin shell elastic model, as well as scaling analysis and regular and singular asymptotic schemes, the problem is examined for small and large deformation limits (relative to the gap between the cylinder and the tube). At the limit of large deformations, forced insertion of the cylinder is shown to involve three distinct regimes and time scales: (i) initial shear dominant regime, (ii) intermediate regime of dominant fluidic pressure and a propagating viscous-peeling front, (iii) late-time quasi-steady flow regime of the fully peeled tube. A uniform solution for all regimes is presented for a suddenly applied constant force, showing initial deceleration and then acceleration of the inserted cylinder. For the case of forced extraction of the cylinder from the tube, the negative gauge pressure reduces the gap between the cylinder and the tube, increasing viscous resistance or creating friction due to contact of the tube and cylinder. Matched asymptotic schemes are used to calculate the dynamics of the near-contact and contact limits. We find that the cylinder exits the tube in a finite time for sufficiently small or large forces. However, for an intermediate range of forces, the radial contact creates a steady locking of the cylinder inside the tube.

Dispersion curves identification and traveling wave control in a weakly coupled impedance tube

Impedance tubes are commonly used for non-destructive measurement method of the acoustic properties of materials. Most physical models neglect the elastic nature of the tube resulting in a single mode propagation up to the cut-off frequency and are thus unable to accurately predict the propagation patterns in the case of liquid-filled tubes. An understating of the dispersion pattern in the latter case is crucial for the success of the acoustic properties estimation procedure. Furthermore, a model-based control can be implemented on the basis of the dispersion relation which is able to enhance the existing methods. This work presents a case study of an air-filled impedance tube. A novel, two-actuators phase-perturbations technique was developed to identify the tube dispersion curves and to compare to analytical models. The accurate identification of dispersion curves was utilized in a successful effort to control a single mode traveling wave ratio by employing a feedforward control algorithm. The success of the case study in the case of a weak acoustic coupling mechanism such as the air-filled impedance tube emphasizes the capabilities when considering a stronger acoustic coupling such as in the liquid-filled impedance tube.

Equilibrium configurations of hard spheres in a cylindrical harmonic potential

A line of hard spheres confined by a transverse harmonic potential, with hard walls at its ends, exhibits a variety of buckled structures as it is compressed longitudinally. Here we show that these may be conveniently observed in a rotating liquid-filled tube (originally introduced by Lee et al. (Adv. Mater., 29 (2017) 1704274) to assemble ordered three-dimensional structures at higher compressions). The corresponding theoretical model is transparent and easily investigated numerically, as well as by analytic approximations. Hence we explore a wide range of predicted structures occurring via bifurcation, of which the stable ones are also observed in our experiments. Qualitatively similar structures have previously been found in trapped ion systems.

Violent expansion of a rising Taylor bubble

The gradual expansion of large bubbles rising in a liquid-filled tube can become violent in the last few seconds before reaching the tube top. This process is responsible for Strombolian volcanic eruptions and for accidents in deep-water oil drilling such as the 2010 Deepwater Horizon explosion.

Testing the causal understanding of water displacement by kea (Nestor notabilis)

Abstract Rooks, Eurasian jays and NC crows have already solved the Aesop’s fable paradigm, using stones to raise a water level to get a previously out of reach reward. Here we test kea parrots on their understanding of water displacement. In Experiment 1, they preferentially chose the water-filled tube over two solid substrates (sand, rocks) within 5 trials. In Experiment 2, they generalised to novel coloured substrates in the first trial. In Experiment 3, confronted with two water-filled tubes, one of which was made unsolvable by preventing the water from rising, none of the kea managed to solve the task. This suggests that their performance in Experiments 1 and 2 was reward association with the liquid-filled tube, without attendance to changes in water level. These results therefore provide no evidence of causal understanding of water displacement and highlight that such an understanding is not required for solving Aesop’s Fable.

Study on the gas-curtain generation characteristics by the multiple gas jets in a liquid-filled tube

To further understand the gas-curtain generation characteristics during the launching process of the underwater guns, a simulated gas-injector with multiple nozzles is designed and the expansion process of these multiple combustion-gas jets is experimentally captured. Experiment results indicate that, with turbulent mixing between the gas jets and the liquid medium, the gas curtain is generated in the observation chamber. Based on the experiment, a three dimensional unsteady model is established to simulate the expansion process of the multiple jets. Numerical result shows, with the injection of the gas jets, pressure declines in the Taylor cavity along the axial direction at the beginning. During the expansion process, the multiple jets contact and interact with each other, and pressure rises in the mixing area. After merging, backflow vortexes interact and converge, and the vortexes move along the axial direction with the expansion of the combustion gas jets.

レーザー誘起マイクロジェットの体積

A highly-focused laser-induced microjet by the rapid vaporization of a small mass of liquid in an open liquid-filled tube is expected to solve problems of conventional needle-free injection devices. For practical use of this microjet, in this study, we investigate experimentally the volume of the microjet V ejected from the tube in order to clarify how the volume V is determined. We conduct two experiments. Firstly, we investigate the relationship between the volume V and the maximum volume of a laser-induced bubble Ω. In our method, the laser-induced bubble grows toward one open side of the tube and pushes the liquid because the tube is closed in the other side of the tube. We anticipate that the volume of the laser-induced bubble is strongly related to the volume of the micorjet V. It is found that the volume of the microjet V is nearly equal to the maximum bubble volume Ω although V is slightly smaller than Ω in all data. Secondly, we investigate the position where the liquid pushed by the bubble breaks up. When the laser-induced bubble shrinks, the bubble partly pulls back the liquid into the tube. The liquid then breaks up at the open end of the tube. Based on aforementioned results, we elucidate the mechanism for determining the volume of the microjet V by considering the pressure evolution inside the laser-induced bubble. Furthermore we construct a model for the volume V with taking into account the volume Vbefore that describes the air volume inside the narrow tube between the open end of a narrow tube and an air-water interface. The model shows a good agreement with the experimental data. These results indicate a possible ability of the volume control in the novel needle-free injection system.

Development and performance evaluation of an electromagnetic-type shock wave generator for lipolysis

This study aims at the design and development of electromagnetic-type intermittent shock wave generation in a liquid. The shock wave generated is focused at a focal point through an acoustic lens. This hardware device mainly consists of a full-wave bridge rectifier, 6 capacitors, a spark gap, and a flat coil. A metal disk is mounted in a liquid-filled tube and is placed in close proximity to the flat coil. Due to the repulsive force existing between the coil and disk shock waves are generated, while an eddy current is induced in the metal disk. Some components and materials associated with the device are also described. By increasing the capacitance content to enhance electric energy level, a highly focused pressure can be achieved at the focal point through an acoustic lens in order to lyse fat tissue. Focused pressures were measured at the focal point and its vicinity for different operation voltages. The designed shock wave generator with an energy intensity of 0.0016 mJ/mm(2) (at 4 kV) and 2000 firings or higher energy intensities with 1000 firings is found to be able to disrupt pig fat tissue.

ANALYTIC APPROACH FOR THE STUDY OF AIR AND/OR LIQUID FILLED GEOMEMBRANE TUBE SECTIONS ON A HORIZONTAL

This study considers an air and liquid-filled geomembrane tube section resting on a horizontal foundation. All quantities are normalized to obtain geometrically similar solutions in the static equilibrium condition. Analytic solutions are expressed in closed form. The solution for the air or liquid-filled tube section is derived systematically as an extreme case of the air and liquidfilled tube section. The validity of these solutions is confirmed by comparing to previous study, and some results are shown for the characteristic parameters and shapes of air and/or liquid-filled cases. Using the result of present study, one can estimate the shape and characteristic parameters of a tube section without numerical integrations or iterations.

Detection of coatings within liquid-filled tubes and containers by mode conversion of leaky Lamb waves

Abstract. In this paper, a new acoustic sensor principle for coating detection within liquid-filled tubes and containers based on mode conversion of leaky Lamb waves is introduced. Leaky Lamb waves are excited and detected by single-phase transducers, which are attached on the outer side of a tube or container. By transmission time and amplitude measurements, coating formation within the liquid-filled tube and container is detected non-invasively. This new sensor principle is subdivided into the separate considerations of Lamb wave excitation, mode conversion and inverse mode conversion. The Lamb wave excitation by a single-phase transducer is visualized by scanning laser Doppler vibrometer imaging. The mode conversion process of leaky Lamb waves is measured by membrane hydrophone measurements and Schlieren visualization; afterwards, the measured emission angles are compared with the theoretical one. The inverse mode conversion process of pressure waves back to leaky Lamb waves is visualized by Schlieren images. By merging the results of Lamb wave excitation, mode conversion and inverse mode conversion, the new sensor concept is explained. Theoretical considerations and measurement results of adhesive tape coating inside a liquid-filled plastic tube and a liquid-filled stainless steel container verify the new acoustic sensor principle. Finally the measuring sensitivity and the technical realization are discussed.

Acoustic attenuation, phase and group velocities in liquid-filled pipes III: Nonaxisymmetric propagation and circumferential modes in lossless conditions

Equations for the nonaxisymmetric modes that are axially and circumferentially propagating in a liquid-filled tube with elastic walls surrounded by air/vacuum are presented using exact elasticity theory. Dispersion curves for the axially propagating modes are obtained and verified through comparison with measurements. The resulting theory is applied to the circumferential modes, and the pressures and the stresses in the liquid-filled pipe are calculated under external forced oscillation by an acoustic source. This provides the theoretical foundation for the narrow band acoustic bubble detector that was subsequently deployed at the Target Test Facility (TTF) of the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL), TN.

Denting and failure of liquid-filled tubes under lateral impact

In this paper, numerical simulation of impact cases of liquid-filled tube impacted by missiles is conducted with a commercial finite element code LS-DYNA, and the results obtained are compared with the experimental data to verify the validity of the numerical simulation model adopted. With the verified numerical method, the processes of dynamic response of a blunt indenter impacting an empty or liquid-filled three-span continuous tubular beam are studied when the parameter such as the indenter's mass, liquid's density or impact velocity is varied and the other conditions are kept the same. The simulation results indicate that the critical perforation energy and the deformation of the wall of the pipe are significantly influenced by the presence of the liquid and the pressure. The liquid filling the tube provides a ‘foundation’ pressure to resist and localize the deformation, which may affect the perforation process and lead to a reduction of the ballistic limit. The simulation results also indicate that the increase of the fluid density filled in the tube will decrease the ballistic limit, but the fluid density must be in some scope. The relationship between the ballistic limit velocity of the tube and the mass of the impact missile is nonlinear in the Cartesian coordinate while it becomes linear through logarithmic transformation.

Acoustic attenuation, phase and group velocities in liquid-filled pipes: Theory, experiment, and examples of water and mercury

Del Grosso's [Acustica 24, 299-311 (1971)] formulation, which predicts the phase speed of propagating axisymmetric modes inside a liquid-filled tube, is here extended to the complex domain in order to predict the attenuation, as well as the sound speed, of the modes as a function of frequency. Measurements of the sound speeds and the attenuations of the modes were performed in a water-filled Poly (methyl methacrylate) (PMMA) tube of internal radius, b=4.445 cm, in the range of the wavenumber-radius product, k(1)b, from 2 to 10. Parts of three or four modes were investigated and the measured sound speeds and the damping of the modes were compared with the theoretical predictions. The theory was then used to estimate the modal sound speeds and attenuations in a stainless-steel pipe filled with mercury having the same dimensions as are used in the Spallation Neutron Source at Oak Ridge National Laboratory, Tennessee.

Onset of cavitation by the strong tension spike from a tube-arrest apparatus

Our earlier paper has identified a wave of Type 1 that is the pressure wave generated in the liquid-filled glass tube through the tube-arrest method by pulling and arresting the tube, when cavitation is prohibited. If cavitation is produced, a wave of Type 2 generally appears. The present paper takes the transition between wave types as indication of cavitation onset, and looks for a liquid parameter which controls the onset. One such an attempt shows the concentration of a dissolved gas in the liquid is the controlling factor with the result that the threshold of cavitation onset decreases with the increase of the concentration. Then a specially designed experiment reveals that possibly the mobility of the gas molecules (and also that of the liquid molecules) transiently affects the threshold so as to induce a large rise and fall in time of hours. The threshold finally settles down to some stable value under atmospheric pressure.

Controlled Transport of Droplets Using Conducting Polymers

The controlled transport and delivery of dichloromethane through platinum mesh coated with dodecylbenzenesulfonate-doped polypyrrole is demonstrated upon in situ electrochemical redox switching. Droplets of dichloromethane were observed to pass freely through the mesh upon reduction of the polymer as a result of the release of the surfactant dopant into the dichloromethane and the change in the surface energy of the polymer. Planar and liquid-filled tube configurations are investigated. These concepts are envisaged to prove useful for fluid control in microfluidic devices, in the preparation of microparticles for drug delivery, and in the development of organic microreactors.