Pipe Conveying Research Articles

Nonlinear Vibrations and Stability Analysis of GPL Reinforced Pipes Conveying Fluid Excited by Arbitrary Initial Conditions: An Optimized Analytical Solution

In this study, nonlinear vibrations and stability of multilayer functionally graded (FG) pipes conveying fluid laying on nonlinear elastic foundation and reinforced by graphene nanoplatelets (GPLs) are investigated with an emphasis on optimized analytical method. Various types of GPL distribution patterns are considered and to estimate the mechanical characteristics of the reinforced pipe the Halpin–Tsai micromechanics theory is applied. The nonlinear differential equation of motion is obtained by using Von–Kármán strain relations in conjunction with the Euler–Bernoulli beam theory and applying Hamilton’s principle. The Galerkin technique has been used for discretizing the partial differential equation. The optimized homotopy analysis method (HAM), as a strong analytical method, is utilized to solve the nonlinear differential equation by considering different initial excitations. The convergence-control parameter is taken into account to guarantee the convergence of the analytical solution. In this study, an exact solution based on HAM for the critical flow velocity and [Formula: see text]th nonlinear frequency is presented. Additionally, series solutions for the nonlinear time responses of the transverse and longitudinal vibrations of fluid-conveying pipe based on optimized HAM are obtained for the first time. In the numerical results, the effects of arbitrary initial conditions and different physical characteristics on the nonlinear frequencies and time responses are extensively examined. It is shown that the nonlinear frequencies and critical flow velocity of the pipe depend not only on the initial excitation amplitude, but also on the entire initial excitation function applied on the pipe.

Hopf Bifurcation of a Standing Cantilever Pipe Conveying Fluid with Time Delay

In this article, the dynamical behavior of a standing cantilever pipe conveying fluid is investigated with time − delay. By applying piezoelectric materials and considering the time delay of voltage, the motion equation is built with motion-limiting constraints and elastic support. The motion equation is discretized into ordinary differential equations by the Galerkin method. A stability analysis of the equilibrium point with three parameters is obtained. The system will lose stability at the equilibrium point and generate Hopf branches. The central manifold theorem and the canonical type theory are used to study the stability of Hopf branching directions and branching period solutions. Finally, numerical results validate the theoretical analysis.

Effect of Shape Memory Alloy Actuation on Parametric Instability in Pipes Conveying Pulsating Fluid

Effect of Shape Memory Alloy Actuation on Parametric Instability in Pipes Conveying Pulsating Fluid

Pipes conveying fluid: A fertile dynamics problem

The early studies on the dynamics of pipes conveying fluid by Feodos’ev, Housner, Benjamin and Païdoussis in the 1950s and 1960s elucidated the basic dynamics of the system. Yet, further studies on variants of the basic system proliferated, so that, by 1993, Pipes Conveying Fluid was deemed to be a model problem in dynamics. The rate of publication of papers on the subject has increased exponentially, with over 1000 papers now published on the subject. This paper presents a very brief review of the fundamentals, and a more extensive review of some very recent work on the subject, which exemplifies the far-ranging variants of the system being studied.

Nonlinear Transient Dynamics of Graphene Nanoplatelets Reinforced Pipes Conveying Fluid under Blast Loads and Thermal Environment

This work aims at investigating the nonlinear transient response of fluid-conveying pipes made of graphene nanoplatelet (GPL)-reinforced composite (GPLRC) under blast loads and in a thermal environment. A modified Halpin–Tsai model is used to approximate the effective Young’s modulus of the GPLRC pipes conveying fluid; the mass density and Poisson’s ratio are determined by using the Voigt model. A slender Euler–Bernoulli beam is considered for modeling the pipes conveying fluid. The vibration control equation of the GPLRC pipes conveying fluid under blast loads is obtained by using Hamilton’s principle. A set of second-order ordinary differential equations are obtained by using the second-order Galerkin discrete method and are solved by using the adaptive Runge–Kutta method. Numerical experiments show that GPL distribution and temperature; GPL weight fraction; pipe length-to-thickness ratio; flow velocity; and blast load parameters have important effects on the nonlinear transient response of the GPLRC pipes conveying fluid. The numerical results also show that due to the fluid–structure interaction, the vibration amplitudes of the GPLRC pipes conveying fluid decay after the impact of blast loads.

Natural Frequencies, Critical Velocity and Equilibriums of Fixed–Fixed Timoshenko Pipes Conveying Fluid

Natural Frequencies, Critical Velocity and Equilibriums of Fixed–Fixed Timoshenko Pipes Conveying Fluid

Influence of Dry Friction on the Dynamics of Cantilevered Pipes Conveying Fluid

A cantilevered pipe conveying fluid can lose stability via flutter when the flow velocity becomes sufficiently high. In this paper, a dry friction restraint is introduced for the first time, to evaluate the possibility of improving the stability of cantilevered pipes conveying fluid. First, a dynamical model of the cantilevered pipe system with dry friction is established based on the generalized Hamilton’s principle. Then the Galerkin method is utilized to discretize the model of the pipe and to obtain the nonlinear dynamic responses of the pipe. Finally, by changing the values of the friction force and the installation position of the dry friction restraint, the effect of dry friction parameters on the flutter instability of the pipe is evaluated. The results show that the critical flow velocity of the pipe increases with the increment of the friction force. Installing a dry friction restraint near the middle of the pipe can significantly improve the stability of the pipe system. The vibration of the pipe can also be suppressed to some extent by setting reasonable dry friction parameters.

Numerical Simulation on Gas-Solid Two-Phase Flow in Horizontal Pneumatic Conveying Pipe Based on DPM Model

The determination of pipe deposition and optimum conveying velocity in pneumatic conveying has an important impact on conveying efficiency. The Euler-Lagrange method DPM model is used to analyse five different particle sizes and densities of small particles, and the flow pattern in the horizontal pipeline at different particle sizes and densities is derived from the graphs of the maximum discrete phase concentration, particle trajectory and discrete phase concentration distribution for each working condition. The simulation results show that the deposition increases with particle size and density, the optimum conveying speed increases with particle size and density, the larger the deposition, the larger the required conveying velocity. The velocity of 2 m/s can make the particles below 20μm suspended transport, the velocity of 4 m/s allows particles with a particle size of 30μm and a density of 1000 kg/m3 or less to be transported in suspension and 6 m/s allows particles with a density of 2000 kg/m3 or less to be transported in suspension. The aim is to provide a reference for the design of pneumatic conveying systems and the selection of the optimum conveying velocity.

Dataset of Flow-Induced Vibrations on a Pipe Conveying Cold Water

Analysis of flow-induced pipe vibrations has been applied in a variety of applications, such as flowrate inference and leak detection. These applications are based on a functional relationship between the vibration features estimated in the pipe walls and the dynamics related to the flow of the substance. The dataset described in this document is comprised of signals acquired using an accelerometer attached to a pipe conveying cold water at specific flowrate values. Tests were carried out under numerals of the ISO 4064-1/2: 2016 standard and were performed in two measurement benches designed for flowmeter calibration, and a total of 80 flowrate values, from 25 L/h to 20,000 L/h, were considered. For each flowrate value, 3 to 6 samples were taken, so that the resulting dataset has a total of 382 signals that contain acceleration values in three axes and a timestamp in microseconds.

Real-time leak detection in oil pipelines using an Inverse Transient Analysis model

Based on Inverse Transient Analysis (ITA) method, a real-time leak detection method is proposed to capture leak location and the associated leak rate in oil pipe conveyance systems. In the proposed approach, location and flow rate of leak (if any), the fluid properties, as well as physical parameters of the system, are calculated in consecutive periods through minimizing the discrepancy between the calculated and measured flow parameters of the system. The method of characteristics is employed to numerically calculate the transient responses of the system and the genetic algorithm is utilized as the optimization engine. The proposed approach was applied to several real pipeline systems in which the required transient flow data are either directly collected from the field or fabricated with a third-party numerical software. Extensive numerical explorations were conducted to investigate the performance of the proposed method in real-time leak detection and to determine the extent to which field data errors, stemming from Supervisory Control and Data Acquisition (SCADA) systems and measurement equipment, affect the leak flow rate and location detectability of the proposed approach. The results show that the proposed approach provides promising results under a variety of transient and steady-state flow conditions even in the case with small leak flow rate of around 2% of the line rate. The results also reveal that the noises in the measurement data and the errors originated from SCADA systems do not significantly compromise the leak detectability of the proposed approach, confirming that the proposed approach can be utilized in practice.

Feasibility Study of Irrigation Development for Sustainable Natural Resources Management Under Changing Climate of Jabi Tehnan Woreda, Amhara Regional State of Ethiopia

Irrigation development has been identified as one of the priority investment sectors in Ethiopia and the government has been implementing a number of efforts that enhance the planning and implementation of small-scale irrigation projects in the country. The aim was to identify the potential, feasibility and profitability of irrigation development for spices production mainly pepper in Jabi woreda of West-Gojjam, Amhara region. It has been observed that majority of the population, live in the rural area with crop production as the main livelihood option, arable land constitutes the largest portion of the ‘woreda’ land use type with cultivated land accounting for 49.8% (58,262 ha), uncultivable land 4.4% or 5,208 ha, natural forest 5.5% or 6,502 ha, bush land /scrubland and or natural pasture accounts 17.6% or 20,662 ha, settlement 9.3% or 10,931 ha and others account 13% or 15,389 ha. The altitude varies from 1400 to 2300 m a.s.l. This woreda is mostly characterized by Haplic Nitisols soil type which is highly productive type of soil in Ethiopia. In most of the fields, the slope gradient ranges from 0% to 5%. The project was studied to irrigate the command area through gravity close pipe conveyance system of surface irrigation with head work of wire division from Lah River. It was studied that about 45,595 ha is suitable irrigable land for surface irrigation of which about 45% (20,105 ha) of suitable land under Lah rive. An agronomic cropping pattern and production calendar of the farming system had identified for the sustainable supply of raw material for the agro-processing plant. Therefore, in the dry season using full irrigation 200ha pepper, 40ha rosemary and 10ha moringa had been under production whereas under rainfed with supplemental irrigation chickpea and field pea 130ha, white and black cumin 40ha and garlic 30ha was produced. The total investment cost of the project was estimated about ETH Birr 48.1 million. The implementation of the proposed irrigation project would require diversion of Lah River and 0.365 m³/sec of water was diverted from the river to the project command area. The minimum flow of the Lah River was 1.99 m³/sec at 95% probability. Thus, downstream impact of abstraction by the project was insignificant. Therefore, it could be concluded that there was no severe or immitigable impacts that could prevent the implementation of the proposed irrigation development.

Nonlinear Resonant Responses, Mode Interactions, and Multitime Periodic and Chaotic Oscillations of a Cantilevered Pipe Conveying Pulsating Fluid under External Harmonic Force

The nonlinear resonant responses, mode interactions, and multitime periodic and chaotic oscillations of the cantilevered pipe conveying pulsating fluid are studied under the harmonic external force in this research. According to the nonlinear dynamic model of the cantilevered beam derived using Hamilton’s principle under the uniformly distributed external harmonic excitation, we combine Galerkin technique and the method of multiple scales together to obtain the average equation of the cantilevered pipe conveying pulsating fluid under 1 : 3 internal resonance and principal parametric resonance. Based on the average equation in the polar form, several amplitude-frequency response curves are obtained corresponding to the certain parameters. It is found that there exist the hardening-spring type behaviors and jumping phenomena in the cantilevered pipe conveying pulsating fluid. The nonlinear oscillations of the cantilevered pipe conveying pulsating fluid can be excited more easily with the increase of the flow velocity, external excitation, and coupling degree of two order modes. Numerical simulations are performed to study the chaos of the cantilevered pipe conveying pulsating fluid with the external harmonic excitation. The simulation results exhibit the existence of the period, multiperiod, and chaotic responses with the variations of the fluid velocity or excitation. It is found that, in the cantilevered pipe conveying pulsating fluid, there are the multitime nonlinear vibrations around the left-mode and the right-mode positions, respectively. We also observe that there exist alternately the periodic and chaotic vibrations of the cantilevered pipe conveying pulsating fluid in the certain range.

Ultra-thin Piezoelectric Lattice for Vibration Suppression in Pipe Conveying Fluid

In this paper, an electrically active, ultra-thin, easy-to-implement, and tunable phononic crystal (PC)-based device is proposed to suppress excessive vibration in pipes conveying fluids. We demonstrate that this device can be realized by periodic implementation of piezoelectric patches with shunt circuits on the pipe acting as PCs for vibration suppression. The mathematical model of the pipe structure is simplified to the form of the Euler–Bernoulli beam, and the transfer matrix method and the finite element method are used to predict the effective bandgap. Conversion between mechanical vibration energy and electrical energy via the piezoelectric effect is observed. As a result, the pipe vibration is suppressed by combined Bragg and electroelastic bandgaps. The comparison with previous literature shows that this ultra-compact device provides a new solution for vibration and noise control in long-distance fluid-conveying pipe systems.

Nonlinear Parametric Vibration of the Geometrically Imperfect Pipe Conveying Pulsating Fluid

In this paper, the novel model of fluid-conveying imperfect pipe supported at both ends is established by considering the geometric imperfection and the geometric nonlinearity induced by mid-plane stretching. The integral-partial differential equation is discretized by the Galerkin method and solved by a fourth-order Runge–Kutta integration algorithm. Compared with the supercritical pitchfork bifurcation of the perfect pipe conveying fluid, the results show that the cusp bifurcation occurs in the imperfect pipe when increasing the flow velocity. Excellent agreement is observed between the numerical results and the analytical results. The two stable asymmetry bifurcation branches bring interesting phenomena in the post-buckling state. The global nonlinear dynamic behaviors of the imperfect pipe are studied by establishing the bifurcation diagrams. The influence of the geometric imperfection amplitude on the nonlinear response is leading to cusp bifurcation comparing with pitchfork bifurcation of the perfect pipe. When pulsation frequency is set as the bifurcation parameter, there are clear nonresonance ranges, low energy resonance ranges and high energy resonance ranges. In the high energy resonance ranges, the first mode vibration coexisting with the sub-harmonic resonance and combination resonance occurs. As the mean flow velocity and pulsation amplitude are set as bifurcation parameters, the vibration of the imperfect pipe becomes more and more complicated. The vibration exhibits far richer dynamic behaviors including periodic, multi-periodic, quasi-periodic, and chaotic motions. The viscoelastic damping can effectively suppress the vibration response and transfer the high energy resonance to the low energy resonance state. The improved model and corresponding results provide useful information for further studying the dynamic behaviors of fluid-conveying pipe with geometric imperfections.

Study on Characteristics of Flow-induced Vibration (FIV) Induced by Gas-liquid Two-phase Flow in the Conveying Pipe

The multi-physics coupling study is carried out by considering the fluctuation of the interphase dynamic interface and its flow characteristics as well as the mechanical properties of the solid structure of the pipeline. By capturing the dynamic interface between gas and liquid, calculating its flow characteristics, combined with the time-history displacement and amplitude of the characteristic monitoring point and the axis of the pipeline, the FIV response characteristics of the basin in the S-type conveying pipe are analyzed. The results show that the dominant area of single gas phase or single liquid phase is not easy to deform and vibrate. The transition and persistence of the flow pattern in the mixed turbulent flow area and the weak regular fluctuation of the flow field in the pipe stimulate the pipe wall to cause stress reaction, leading to the time-history vibration with great difference in the pipe.

Experimental Study of Vibration on Pipe Conveying Fluid at Different End Conditions for Different Fluid Temperatures

Dynamic behavior of a copper pipe conveying fluid at different fluid temperatures is investigated experimentally. Three types of supports are used, which are simply support - simply support, fixed – fixed support and fixed – free support. The effect of the support's types on the frequency and the amplitude of vibration for the pipe conveying the fluid are studied for various flow temperature. These vibration characteristics were tested at temperatures 50, 65 and 80 ºC

Impact of Crack Length into Pipe Conveying Fluid Utilizing Fast Fourier transform Computer Algorithm

<p>One of the most prominent problems experienced by the oil facilities is leakage of oil from the pipes. This problem caused 55% of oil refineries to be shut off. Oil leakage is a common problem that often results in oil waste, damage, and hazard to public health. Therefore, it is necessary to use Modern technologies to reduce this phenomenon and avoid them in advance. Pipes that convey fluids have many uses in various industries and living facilities. Risk increases when the fluid inside the pipe is flammable. In this work, main case that cause damage to the pipe, longitudinal crack is investigate.This work presents a new experimental model based on computer applications with a Fast Fourier transform (FFT) algorithm for testing the effect of longitudinal crack length by frequency and ultrasonic measurements to measure fluid velocity. The method is used for plastic pipe with 2 cm internal diameter, 3 cm external diameter, and 1 m length. The modulus of elasticity of the material is 800 N/mm2 according to the ISO 178 test method. The pipe conveys oil with simply supported ends. The results show that FFT model shows better features compared with other ways that depends on visual inspection or localized measurements which gave an external perception of pipeline damage. FFT model offers a reliable and cheap style for ensuring pipeline integrity and warning the risks before its occurrence. From the observations made the fundamental natural frequency (FNF) decreases by increasing of crack length in the pipe that conveys fluid</p>

Buckling Analysis on a Pipe Conveying Fluid under Two Stresses

Pressure pipes have broad applications in aviation, space flight, mechanical engineering, industrial and civil architecture etc. Instability destruction is their main failure mode. Firstly, in this paper, a complex fluid-solid coupling problem was simplified as a buckling problem of a pipe under two stresses which were along the pipe wall. The two stresses consisted of a compressive stress which was perpendicular to the pipe wall and a tangential stress which was parallel to the pipe wall. Secondly, the buckling performs of the pressured pipe were discussed by finite element analysis method under a working state and an off-working state, respectively. Some obtained conclusions were drawn as follows by the analysis in this paper.1). Provided the tangential stress is unchanged, by increasing compressive stress eigenvalue buckling critical load increases and nonlinear buckling critical load decreases.2). Provided the compressive stress is unchanged, when the direction of the tangential stress is same as that of the axial pressure, by increasing the absolute value of tangential stress the buckling critical load decreases; provided the compressive stress is unchanged, when the direction of the tangential stress is in the opposite direction of the axial pressure, by increasing the absolute value of tangential stress the buckling critical load increases.

Forced Vibration Analysis of Fluid Conveying Pipe with Both Ends Supported

Forced Vibration Analysis of Fluid Conveying Pipe with Both Ends Supported

The Analysis of Nonlinear Vibrations of Top-Tensioned Cantilever Pipes Conveying Pressurized Steady Two-Phase Flow under Thermal Loading

This paper studied the nonlinear vibrations of top-tensioned cantilevered pipes conveying pressurized steady two-phase flow under thermal loading. The coupled axial and transverse governing partial differential equations of motion of the system were derived based on Hamilton’s mechanics, with the centerline assumed to be extensible. Using the multiple-scale perturbation technique, natural frequencies, mode shapes, and first order approximate solutions of the steady-state response of the pipes were obtained. The multiple-scale assessment reveals that at some frequencies the system is uncoupled, while at some frequencies a 1:2 coupling exists between the axial and the transverse frequencies of the pipe. Nonlinear frequencies versus the amplitude displacement of the cantilever pipe, conveying two-phase flow at super-critical mixture velocity for the uncoupled scenario, exhibit a nonlinear hardening behavior; an increment in the void fractions of the two-phase flow results in a reduction in the pipe’s transverse vibration frequencies and the coupled amplitude of the system. However, increases in the temperature difference, pressure, and the presence of top tension were observed to increase the pipe’s transverse vibration frequencies without a significant change in the coupled amplitude of the system.