Pipe Conveying Research Articles

Study on the Influence of Gravity Factor on Parametric Resonance of Pipe Conveying Fluid

The averaging method has been applied to calculate the critical conditions of parametric resonance instability of the first order mode shape of clamped-clamped and pinned-pinned pipes conveying fluid. The influence of gravity factor on parametric resonance of pipe conveying fluid, with different supporting forms and different flow velocity, has been studied based on the comparison results of gravity factor being considered and neglected. It is concluded that gravity factor has a greater influence on parametric resonance region of pinned-pinned pipe than the one of clamped-clamped pipe, and, at a higher flow velocity, gravity factor is more influential to both pinned-pinned pipe and clamped- clamped one.

0818 内部流による弾性送水管の非線形横振動 (複数の固有振動が不安定となる場合)(OS05-4 機械力学(2)音と振動の解析・制御技術,オーガナイズドセッション 5:「機械力学(2)音と振動の解析・制御技術」)

0818 内部流による弾性送水管の非線形横振動 (複数の固有振動が不安定となる場合)(OS05-4 機械力学(2)音と振動の解析・制御技術,オーガナイズドセッション 5:「機械力学(2)音と振動の解析・制御技術」)

The Influence of Supported and Restrained Elastic Coefficient on the Stability of Fluid Conveying Pipe

The dynamic stability of fluid conveying piping system under different supporting conditions, considering the fluid structures interaction, was investigated. The expression of vertical vibration mode-function of commonly supported piping system was derived from its boundary condition of the similar beam. Firstly, considering the effects of Kelvin-Voigt visco-elastic coefficient of pipe, fluid pressure and axially sectional force of pipe, the motion equation of the piping system was established. Secondly, the equation was discretized by Galerkin method according with its similar supporting conditions of beam. Thirdly, the expression of critically instable flow velocity was obtained. Lastly, the stability of the piping system was analyzed by using the dynamical simulation methods. The numerical results showed that the critically instable flow velocity is proportional conversely to supported linear spring coefficients, but is proportional to restrained torsion spring coefficients.

An Active Control Method for Chaotic Motion of Fluid Conveying Pipe under Harmonic Excitation of Supports

The chaotic motion of a single mode system of the fixed supported pipe at two ends under the base excitation was actively controlled by introducing the feedback of notch filter. The equations of both homoclinic and periodic orbits of the unperturbed system were derived firstly, and then the corresponding Melnikov functions were deduced. Based on the conditions that the Melnikov functions corresponding to the homoclinic and periodic orbits respectively had themselves simple zeros, the conditions that parameters should satisfy to introduce the chaotic motion of the system into periodic orbits could be obtained. Lastly, numerical simulation was used for the response of the perturbed system, and the simulation results showed that the system’s chaotic motion can be successfully induced to periodic motion. For different feedback gains of the notch filter, the responses of the system would converge on different stable periodic solutions.

Feasibility Evaluation of Pressurized Irrigation in Canal Commands

India has one of the largest and most ambitious irrigation programme in the world with net irrigated area exceeding 47 million hectares. However, the overall project efficiency from the headwork to the farmer’s field has been quite low which leads to not only poor utilization of irrigation potential created at huge cost, but also aggravates the degradation of soil and water resources and thereby endangers the sustainability of agricultural production system. As the cost of creating additional irrigation potential in terms of financial, human and environmental aspects has increased tremendously, need of the hour is to increase the irrigation efficiency of existing projects and use saved water for irrigating new areas or meeting the demand of non-agricultural sector. The contribution of application efficiency to poor irrigation efficiency is quite high and therefore increasing application efficiency by a shift in application method from surface to pressurized system has potential of vastly improving irrigation efficiency. To evaluate feasibility of this concept, a pilot study was initiated at Water Technology Centre for Eastern Region, Bhubaneswar, on one outlet of a minor irrigation command. The system has been designed in such a way that it provides pipe conveyance and surface irrigation for rice cultivation during monsoon season and pressurized irrigation during post monsoon period through a hybrid system of sprinkler and drip with four outlets for sprinkler irrigating 2.8 ha area and two outlets for drip irrigating 1.9 ha area. The system is also capable of providing irrigation through drip to part of a command during summer for third crop using water stored in service reservoir after the canal is closed in first week of April. To take care of sediment in the canal water, there are three stages of filtration: first by hydrocyclone filter which filters heavy suspended materials viz. sand, silt, etc., then by the sand filter and finally by the screen filter. The filtration at three stages reduces the turbidity to the desired level. It has been found that three-stage filtration reduced the turbidity to two NTU which is within permissible limit. Considering the cost of water saved, a benefit-cost ratio of the system was found out to be 1.126. This B: C ratio can be further increased by increasing the productivity of the fish and papaya in service reservoir area and better crop management during summer season.

618 内部流による弾性送水管の座屈 : 高周波脈動流の影響(OS4-4 機械のダイナミクス4,オーガナイズドセッション:4)

618 内部流による弾性送水管の座屈 : 高周波脈動流の影響(OS4-4 機械のダイナミクス4,オーガナイズドセッション:4)

内部流による弾性送水管の非線形横振動 : 管下端がばね支持されている場合の非線形安定性(機械力学,計測,自動制御)

内部流による弾性送水管の非線形横振動 : 管下端がばね支持されている場合の非線形安定性(機械力学,計測,自動制御)

Application of formation pressure while drilling in Australia: North West Shelf examples

Since its introduction in the 1950s, the point-by-point wireline formation pressure measurement technique has been successfully used for formation evaluation and reservoir management, and has been an essential input into reservoir models. In exploration and appraisal wells, where depletion has not yet affected the reservoir, vertical pressure profiling can be used for fluid gradient determination that may be interpreted in terms of fluid densities and contacts. In a dynamic producing environment pressure measurements can help to identify vertical and horizontal boundaries and communication. Measurement of pressure distribution along the borehole was historically done with wireline instruments or, in difficult logging conditions, with wireline instruments conveyed by drill pipe. In some environments, especially in highly deviated and S-shaped wells or unconsolidated formations, drill pipe conveyance of wireline formation pressure testers introduces significant operational risk. Formation Pressure While Drilling (FPWD), introduced in 2003, offers a new cost-effective solution for gathering formation pressure data. FPWD is a new method to directly measure formation pore pressure as the well is being drilled, extending its application beyond traditional fluid typing, contacts and compartmentalisation determination to well control and drilling optimisation. The market for FPWD is developing rapidly with all major service companies providing their own implementations of the technology. The next step in the evolution of FPWD technology—sampling while drilling—is not commercially available yet, but this is just a matter of time. The case history presented in this extended abstract is an example of the application and lessons learned from the FPWD service used in one of the oil fields on the North West Shelf, Australia.

Non-Planar Vibrations of a Pipe Conveying Fluid with a Spring-Supported End

A theoretical and experimental investigation was conducted into the spatial behavior of a flexible pipe through which fluid flows and which is built-in at one end and has an asymmetric spring-support at the other end. Planar, non-planar and beating type vibrations occur in such a system and depend on the flow velocity and spring coefficients. Equations governing amplitudes and the phase were derived and used to clarify numerically the above specific cases. Corresponding actual pipe displacements were then measured experimentally using an image processing system employing two CCD cameras. Qualitative agreement was demonstrated between the experimental and theoretical results.

1001 内部流による弾性送水管の非線形横振動 : 複数のモードが励振される場合(OS12 機械の静音化と低振動化,オーガナイズドセッション:12 機械の静音化と低振動化)

1001 内部流による弾性送水管の非線形横振動 : 複数のモードが励振される場合(OS12 機械の静音化と低振動化,オーガナイズドセッション:12 機械の静音化と低振動化)

Pneumatic Transport of Granular Materials in an Inclined Conveying Pipe: Comparison of Computational Fluid Dynamics−Discrete Element Method (CFD−DEM), Electrical Capacitance Tomography (ECT), and Particle Image Velocimetry (PIV) Results

This paper presents three flow patternsdispersed flow, reverse flow, and half-ring flowin the post-bend region of a 45° inclined pneumatic conveying pipe. Solid concentration and velocity distribution were measured using electrical capacitance tomography (ECT), particle image velocimetry (PIV), and a high-speed camera. The axial velocity of particles and solid transverse motion in the pipe cross section were obtained using a modified cross-correlation method from the ECT data for the three flow patterns. The axial velocity profile over the pipe cross section was compared with data obtained from the PIV system. In particular, emphasis has been placed on the characterization of the reverse-flow pattern, where negative values of solid velocities were observed. By analyzing the images captured with the high-speed camera, three distinct regions in the solid phase of the reverse-flow regime may be discerned. A dense region with high solid concentration formed next to the bottom wall of the inclined conveying pipe, while a dilute region with a relatively low solid concentration formed near the center of the pipe. Reverse flow was observed to occur predominantly in the dense region and a transition region between the two. Finally, the dynamic forces acting on single particles were analyzed for the three flow patterns. This analysis showed that the phenomena of reverse-flow and half-ring flow structure formation may be attributed to the effects of electrostatics. This finding has also been validated with results of numerical simulations performed in the present study.

Studies on Canal Water Based Pressurized Irrigation System in a Minor Irrigation Command

The flow based minor irrigation systems are common in the plateau areas of eastern India. However due to rolling topography and coarse soil texture, the irrigation efficiency is quite poor. With rolling topography, a scope exists to shift from surface irrigation to hybrid application system comprising gravity fed pipe conveyance and surface irrigation for rice in monsoon season and pumped pressurized irrigation system for post-monsoon crops. A system comprising an adjunct reservoir, a common mainline with option of sprinkler and drip at desirable location was designed for one outlet of a minor irrigation system and was evaluated for its hydraulics and irrigation efficiency. The system reduced the turbidity of the canal water from 11-16 NTU to 2-3 NTU in three stages i.e. adjunct reservoir, catchwell and filtration unit. It was found that the irrigation efficiency of sprinkler and drip irrigation systems were 77.2% and 90.19% respectively in comparison to 46.14% in case of surface irrigation system. The uniformity coefficients of sprinkler irrigation system and emission uniformity of drip irrigation system were 81.4% and 94.2% respectively. Thus the above system can be successfully used in minor irrigation commands, for increasing irrigation efficiency as well as yields. The economic analysis of the system indicated that if the cost of hybrid drip and sprinkler irrigation system is less than Rs. 38,000.00 /ha, then saving water through this system will be more economical.

Stability Analysis of a Pipe Conveying Periodically Pulsating Fluid Using Finite Element Method

It is well known that the constant velocity of the fluid in a pipe which makes the lowest natural frequency zero is called critical velocity. The pipe becomes unstable when the fluid in a pipe is faster than the critical velocity. If the velocity of the fluid in a pipe varies with time, however, the instability of a pipe will occur even though the mean velocity of the fluid is below the critical velocity. In this paper, a new method for the stability analysis of a pipe conveying fluid which pulsates periodically is presented. The finite element model is formulated to solve the governing equation numerically. The coupled effects of several harmonic components in the velocity of fluid to a pipe is discussed. A new unstable region is shown in this paper which will not appear in the stability analysis of single pulsating frequency. The results of the stability analysis presented in this paper are verified by the time domain anlysis.

Lateral Vibration of a Pipe Conveying Fluid

Lateral Vibration of a Pipe Conveying Fluid

Finite Element Analysis of Forced Vibration for a Pipe Conveying Harmonically Pulsating Fluid

It is well known that the natural frequencies of a pipe become lower as uniform internal fluid velocity increases. The pipe becomes unstable if the fluid is faster than the critical velocity. But in the case of a pipe conveying harmonically pulsating fluid, resonances will occur even though the mean velocity of the fluid is below the critical velocity. Therefore, for improved analysis, the effects of pulsating fluid in the pipe should also be taken into consideration. In this study, a finite element formulation for the pipe was carried out while taking into consideration the effects of the fluid pulsating harmonically in the pipe. The damping and stiffness matrices in the finite element equation vary with time. A stability analysis based on the Bolotin method was carried out. And, a method to directly estimate the forced response of the pipe that does not need to solve a time data from time-variant system is presented. Several numerical examples are given in this paper that validate of this method.

Beating Phenomena of a Pipe Conveying Fluid with a Spring Supported End

Beating Phenomena of a Pipe Conveying Fluid with a Spring Supported End

Nonplanar Vibration of a Pipe Conveying Fluid (In Case of an Asymmetrical Spring Supported End)

Spatial behavior of a pipe conveying fluid is examined theoretically and experimentally under the condition that the pipe has an asymmetrical spring supported end. Three first-order ordinary differential equations, which govern the amplitudes and phase of the self-excited lateral pipe vibration, are derived from the nonlinear nonself-adjoint partial differential equations by the Liapnov-Schmidt reduction. The planar and nonplanar motion of the pipe exist depending on the flow velocity and the perturbed parameter of the spring coefficient. Furthermore the experiments were conducted with the silicon rubber pipe conveying water. The spatial displacements of the pipe were measured by the image processing system, which was based on the images from two CCD cameras. The typical feature of the self-excited pipe vibration, as predicted by the theory, was confirmed qualitatively.

회전하는 유체이송 외팔 파이프의 동특성 해석

회전하는 유체이송 외팔 파이프의 동특성 해석

Nonlinear Dynamics of Fluid Conveying Pipe with Pulsating Flow. In Case of an Elastically Supported End.

Flow-induced vibration of a fluid conveying pipe with a spring supported end, is examined theoretically and experimentally under the condition that the fluid velocity has a small pulsating comnonent. The parametric resonance of the lateral deflection of the pipe is occured due to the pulsating flow. In this paper, two first-order ordinary differential equations, which govern the amplitude and phase of the parametric resonance, are derived from the nonlinear nonself-adjoint partial differential equation by the Liapnov-Schmidt reduction. The effect of the spring support on the nonlinear stability is discussed with the reduced evolutional equation, which is obtained with the method of center manifold. Furthermore the experiments were conducted with the silicon rubber pipe conveying water. The lateral deflection of the pipe was measured by the image processing system which was based on the images from two CCD cameras. The typical feature of the parametric resonance, which was predicted in the theory, was confirmed qualitatively.

유체를 이송하는 직선관의 진동 해석을 위한 새로운 비선형 모델링

유체를 이송하는 직선관의 진동 해석을 위한 새로운 비선형 모델링