Pump valve pipeline vibration brings serious safety hazards to the operation of the equipment,for the pump valve system in the process of variable flow,variable speed,variable openings lead to excessive pipeline vibra...Pump valve pipeline vibration brings serious safety hazards to the operation of the equipment,for the pump valve system in the process of variable flow,variable speed,variable openings lead to excessive pipeline vibration.An active damping device(ADD)is used to the vibration of the pump valve pipeline system to apply the control force,to achieve the active control of the pipeline vibration.A pump-valve pipeline vibration test bench was built to compare the control effect of active damping device on pipeline vibration under different pump valve working conditions,and the results show that applying ADD control could effectively suppress the vibration of the pump valve pipeline and enhance the stability of the equipment during operation.At different pump operating rotation frequencies,the vibration amplitude of the pump valve pipeline in working frequency and its multiple frequencies are also effectively suppressed,with the maximum amplitude reduction of more than 60%.For the valve vibration caused by different operating openings,the vibration of the highest reduction of 68%,and the centrifugal pump drive shaft vi-bration reduced by up to 73%,which provides a new idea for vibration control of pump valve pipeline system.展开更多
The design of aircraft hydraulic pipeline system is limited by many factors,such as the integrity of aviation structure or narrow installation space,so the limited clamp support position should be considered.This pape...The design of aircraft hydraulic pipeline system is limited by many factors,such as the integrity of aviation structure or narrow installation space,so the limited clamp support position should be considered.This paper studied the frequency adjustment and dynamic responses reduction of the multi-support pipeline system through experiment and numerical simulation.To avoid the resonance of pipeline system,we proposed two different optimization programs,one was to avoid aero-engine working range,and another was to avoid aircraft hydraulic pump pulsation range.An optimization method was introduced in this paper to obtain the optimal clamp position.The experiments were introduced to validate the optimization results,and the theoretical optimization results can agree well with the test.With regard to avoiding the aero-engine vibration frequency,the test results revealed that the first natural frequency was far from the aero-engine vibration frequency.And the dynamic frequency sweep results showed that no resonance occurred on the pipeline in the engine vibration frequency range after optimization.Additionally,with regard to avoiding the pump vibration frequency,the test results revealed that natural frequencies have been adjusted and far from the pump vibration frequency.And the dynamic frequency sweep results showed that pipeline under optimal clamp position cannot lead to resonance.The sensitivity analysis results revealed the changing relationships between different clamp position and natural frequency.This study can provide helpful guidance on the analysis and design of practical aircraft pipeline.展开更多
Gases have long been used for medical applications across the world. Medical oxygen, one of the most important medical gases, has been widely applied both in hospitals and at home. It is defined as a drug and its pipe...Gases have long been used for medical applications across the world. Medical oxygen, one of the most important medical gases, has been widely applied both in hospitals and at home. It is defined as a drug and its pipeline distribution systems are medical devices whose quality and management should conform to specific standards. In China, several deficiencies relating to the distribution and use of medical oxygen, which may lead to a number of fatal accidents like gas pipeline explosion and cause illicit product use, have been revealed in health facilities. They are the result of a lack of the relevant standards, management and practical experiences. To overcome these failures, it might be interesting to refer to the experience and regulations of other countries, for example, those of France.展开更多
Classical beat phenomenon has been observed in most combined systems. The focus of this paper is to provide a better understanding of this phenomenon in an offshore pile-supported pipeline system. The beat phenomeon i...Classical beat phenomenon has been observed in most combined systems. The focus of this paper is to provide a better understanding of this phenomenon in an offshore pile-supported pipeline system. The beat phenomeon is caused by the coupling movement of the pipeline and its vertical pile support under certain conditions. It can induce excessive vibration and cause fatigue failure at pipe elbow. However, in some circumstances it does not exist. Numerical results in both frequency and time domains are presented to elucidate this phenomenon in a combined pipeline system. The conclusions of this paper could give constructive guidance to future design of simply supported pipeline systems.展开更多
Vibrations in aircraft hydraulic pipeline system,due to multi-source excitation of high fluid pressure fluctuation and serious vibration environment of airframe,can cause the pipeline system vibration failures through...Vibrations in aircraft hydraulic pipeline system,due to multi-source excitation of high fluid pressure fluctuation and serious vibration environment of airframe,can cause the pipeline system vibration failures through overload in engineering field.Controlling the vibrations in hydraulic pipeline is a challenging work to ensure the flight safety of aircraft.The common vibration control technologies have been demonstrated to be effective in typical structures such as aerospace structures,shipbuilding structures,marine offshore structures,motor structures,etc.However,there are few research literatures on vibration control strategies of aircraft hydraulic pipeline.Combining with the development trend of aircraft hydraulic pipeline system and the requirement of vibration control technologies,this paper provides a detailed review on the current vibration control technologies in hydraulic pipeline system.A review of the general approaches following the passive and active control technologies are presented,which are including optimal layout technique of pipeline and clamps,constrained layer damping technique,vibration absorber technique,hydraulic hose technique,optimal pump structure technique,and active vibration control technique of pipeline system.Finally,some suggestions for the application of vibration control technologies in engineering field are given.展开更多
There exists a lot of research on the nonlinear vibration of the pipeline system with different boundary conditions.To the best of our knowledge,little research on the actual constraint of the clamp has been performed...There exists a lot of research on the nonlinear vibration of the pipeline system with different boundary conditions.To the best of our knowledge,little research on the actual constraint of the clamp has been performed.In this paper,according to hysteresis loops of the clamp obtained from experimental test,the simplified bilinear stiffness and damping model is proposed.Then the Finite Element(FE)model of L-type pipeline system with clamps is established using Timoshenko beam theory in combination with aforementioned stiffness-damping model.Both hammering and shaker tests verify the FE model via the comparisons of natural frequencies and vibration responses.The results show that the maximum errors of natural frequencies and vibration responses are about 8.31%and 17.6%,respectively.The proposed model can simulate the dynamic characteristics of the L-type pipeline system with clamps well,which is helpful to provide some guidance for the early design stage of pipeline in aero-engine.展开更多
The fluid-structure interaction(FSI)in aircraft hydraulic pipeline systems is of great concern because of the damage it causes.To accurately predict the vibration characteristic of long hydraulic pipelines with curved...The fluid-structure interaction(FSI)in aircraft hydraulic pipeline systems is of great concern because of the damage it causes.To accurately predict the vibration characteristic of long hydraulic pipelines with curved segments,we studied the frequency-domain modeling and solution method for FSI in these pipeline systems.Fourteen partial differential equations(PDEs)are utilized to model the pipeline FSI,considering both frequency-dependent friction and bending-flexibility modification.To address the numerical instability encountered by the traditional transfer matrix method(TMM)in solving relatively complex pipelines,an improved TMM is proposed for solving the PDEs in the frequency domain,based on the matrix-stacking strategy and matrix representation of boundary conditions.The proposed FSI model and improved solution method are validated by numerical cases and experiments.An experimental rig of a practical hydraulic system,consisting of an aircraft engine-driven pump,a Z-shaped aero-hydraulic pipeline,and a throttle valve,was constructed for testing.The magnitude ratio of acceleration to pressure is introduced to evaluate the theoretical and experimental results,which indicate that the proposed model and solution method are effective in practical applications.The methodology presented in this paper can be used as an efficient approach for the vibrational design of aircraft hydraulic pipeline systems.展开更多
The purpose of this paper is to adopt the uniform confidence method in both water pipeline design and oil-gas pipeline design.Based on the importance of pipeline and consequence of its failure,oil and gas pipeline can...The purpose of this paper is to adopt the uniform confidence method in both water pipeline design and oil-gas pipeline design.Based on the importance of pipeline and consequence of its failure,oil and gas pipeline can be classified into three pipe classes,with exceeding probabilities over 50 years of 2%,5% and 10%,respectively.Performance-based design requires more information about ground motion,which should be obtained by evaluating seismic safety for pipeline engineering site.Different from a city＇s water pipeline network,the long-distance oil and gas pipeline system is a spatially linearly distributed system.For the uniform confidence of seismic safety,a long-distance oil and pipeline formed with pump stations and different-class pipe segments should be considered as a whole system when analyzing seismic risk.Considering the uncertainty of earthquake magnitude,the design-basis fault displacements corresponding to the different pipeline classes are proposed to improve deterministic seismic hazard analysis（DSHA）.A new empirical relationship between the maximum fault displacement and the surface-wave magnitude is obtained with the supplemented earthquake data in East Asia.The estimation of fault displacement for a refined oil pipeline in Wenchuan MS8.0 earthquake is introduced as an example in this paper.展开更多
The ever-increasing deepwater oil and gas development in the Qiongdongnan Basin,South China Sea has initiated the need to evaluate submarine debris-flow hazard risks to seafloor infrastructures.This paper presents a c...The ever-increasing deepwater oil and gas development in the Qiongdongnan Basin,South China Sea has initiated the need to evaluate submarine debris-flow hazard risks to seafloor infrastructures.This paper presents a case study on evaluating the debris-flow hazard risks to the planned pipeline systems in this region.We used a numerical model to perform simulations to support this quantitative evaluation.First,one relict failure interpreted across the development site was simulated.The back-analysis modeling was used to validate the applicability of the rheological parameters.Then,this model was applied to forecast the runout behaviors of future debris flows originating from the unstable upslope regions considered to be the most critical to the pipeline systems surrounding the Manifolds A and B.The model results showed that the potential debris-flow hazard risks rely on the location of structures and the selection of rheological parameters.For the Manifold B and connected pipeline systems,because of their remote distances away from unstable canyon flanks,the potential debris flows impose few risks.However,the pipeline systems around the Manifold A are exposed to significant hazard risks from future debris flows with selected rheological parameters.These results are beneficial for the design of a more resilient pipeline route in consideration of future debris-flow hazard risks.展开更多
Losses due to hazards are inevitable and numerical simulations for estimations are complex.This study proposes a model for estimating correlated seismic damages and losses of a water supply pipeline system as an alter...Losses due to hazards are inevitable and numerical simulations for estimations are complex.This study proposes a model for estimating correlated seismic damages and losses of a water supply pipeline system as an alternative for numerical simulations.The common approach in other research shows average damage spots per mesh estimated statistically independent to one another.Spatially distributed lifeline systems,such as water supply pipelines,are interconnected,and seismic spatial variability affects the damages across the region;thus,spatial correlation of damage spots is an important factor in target areas for portfolio loss estimation.Generally,simulations are used to estimate possible losses;however,these assume each damage behaves independently and uncorrelated.This paper assumed that damages per mesh behave in a Poisson distribution to avoid over-dispersion and eliminate negative losses in estimations.The purpose of this study is to obtain a probabilistic portfolio loss model of an extensive water supply area.The proposed model was compared to the numerical simulation data with the correlated Poisson distribution.The application of the Normal To Anything(NORTA)obtained correlations for Poisson Distributions.The proposed probabilistic portfolio loss model,based on the generalized linear model and central limit theory,estimated the possible losses,such as the Probable Maximum Loss(PML,90%non-exceedance)or Normal Expected Loss(NEL,50%non-exceedance).The proposed model can be used in other lifeline systems as well,though additional investigation is needed for confirmation.From the estimations,a seismic physical portfolio loss for the water supply system was presented.The portfolio was made to show possible outcomes for the system.The proposed method was tested and analyzed using an artificial field and a location-based scenario of a water supply pipeline system.This would aid in pre-disaster planning and would require only a few steps and time.展开更多
When designing a complex pipeline with long distance and multi-supports for offshore platform,it is necessary to analyze the vibration characteristics of the complex pipeline system to ensure that there is no harmful ...When designing a complex pipeline with long distance and multi-supports for offshore platform,it is necessary to analyze the vibration characteristics of the complex pipeline system to ensure that there is no harmful resonance in the working conditions.Therefore,the optimal layout of support is an effective method to reduce the vibration response of hydraulic pipeline system.In this paper,a developed dynamic optimization method for the complex pipeline is proposed to investigate the vibration characteristics of complex pipeline with multi-elastic supports.In this method,the Kriging response surface model between the support position and pipeline is established.The position of the clamp in the model is parameterized and the optimal solution of performance index is obtained by genetic algorithm.The number of clamps and the interval between clamps are considered as the constraints of layout optimization,and the optimization objective is the natural frequencies of pipeline.Taking a typical offshore pipeline as example to demonstrate the effectiveness of the proposed method,the results show that the vibration performance of the hydraulic pipeline system is distinctly improved by the optimization procedure,which can provide reasonable guidance for the design of complex hydraulic pipeline system.展开更多
This work focuses on the development and implementation of a simulation-based approach for the detection of partial and extended blockages within an edible oil pipeline system. Blockages, whether partial or extended, ...This work focuses on the development and implementation of a simulation-based approach for the detection of partial and extended blockages within an edible oil pipeline system. Blockages, whether partial or extended, pose a significant operational and safety risks. This study employs computational fluid dynamics (CFD) simulations to model the flow behaviour of edible oil through pipeline under varying conditions. It leverages advanced computational fluid dynamics (CFD) simulations to analyze pressure, velocity, and temperature variations along the pipeline. By simulating scenarios with different blockage characteristics, there is establishment of distinctive patterns indicative of partial and extended obstructions. Through extensive analysis of simulation data, sensing element, and monitoring system, processing signal input and response output, the system can accurately pinpoint the location and severity of blockages, providing crucial insights for timely intervention. The detection system represents a significant advancement in pipeline monitoring technology, offering a proactive and accurate approach to identify blockages and mitigate potential risks and ensure the uninterrupted flow of edible oil, thereby enabling timely intervention and maintenance.展开更多
The global discussion surrounding Functionally Graded Materials(FGMs)highlights their unique and diverse micro-material properties that result from varying two or more materials in a strategic combination profile.Thes...The global discussion surrounding Functionally Graded Materials(FGMs)highlights their unique and diverse micro-material properties that result from varying two or more materials in a strategic combination profile.These combinations produce distinct physical and chemical characteristics.Changes in these characteristics may occur continuously,referred to as a gradient function,or discontinuously as a stepwise function.The changes can appear within homogeneous or heterogeneous material geometries.The variation in material properties depends on the volume fraction index function.This variation can occur in 1D,2D,or 3D,either in the thickness or length direction within a material model.The vacuum in the review study on mechanically toughened and thermally resistant Functionally Graded(FG)pipelines prompted the current review study.This study addresses the absence of an appropriate variational function for FG cylindrical pipelines.It proposes a gradation function pattern to improve pipeline structural performance.An appraisal based on relevant FGM literature was conducted to improve the temperature differentials in traditional composite materials and stress-related issues in carbon steel pipelines.The review identifies specific FGM property variations that reduce failures that are possible in conventional materials.Reviewed articles and evaluation procedures followed the 2020 PRISMA guidelines.Literature was obtained from Scopus,Connected Papers,and other reputable sources.The study also discusses potential FG pipelines for gas and green energy transportation.The reviewed literature establishes the context for this research and addresses the gap in 3D FG model variation functions involving multiple materials.展开更多
This article focuses on the optimization of water supply and drainage systems,involving theories such as hydraulic models of pipeline systems and multi-objective collaborative optimization.It introduces the system dyn...This article focuses on the optimization of water supply and drainage systems,involving theories such as hydraulic models of pipeline systems and multi-objective collaborative optimization.It introduces the system dynamics model of sewage treatment facility expansion.Elaborating on detection technology,construction of an intelligent operation and maintenance system,and factors to be considered for sewage plant expansion,it emphasizes the importance of collaborative development and verifies benefits through the PSR model.展开更多
In ultraviolet cured-in-place-pipe(UV-CIPP)pipeline rehabilitation,resin performance critically determines repair effectiveness.Current UV-curable resins exhibit high volatile organic compound(VOC)emissions and inadeq...In ultraviolet cured-in-place-pipe(UV-CIPP)pipeline rehabilitation,resin performance critically determines repair effectiveness.Current UV-curable resins exhibit high volatile organic compound(VOC)emissions and inadequate post-cure toughness,which compromise fatigue resistance during service.To address these issues,we synthesized hydroxyl-terminated polyurethane acrylate prepolymers using diphenylmethane diisocyanate(MDI),polypropylene glycol(PPG),and hydroxyethyl methacrylate(HEMA).Fourier transform infrared spectroscopy(FTIR)confirmed successful prepolymer synthesis.We developed UV-curable resins by incorporating various crosslinking monomers and optimized the formulations through mechanical property analysis.Testing revealed that the polyurethane-acrylic UV-cured resin system combines polyurethane's mechanical excellence with acrylics'high UV-curing activity.The PPG200/MDI/HEMA formulation achieved superior performance,with a tensile strength of 55.31 MPa,an impact toughness of 22.7 kJ/m^(2),and a heat deflection temperature(HDT)of 132℃.The optimized system eliminates volatile components while maintaining high reactivity,addressing critical limitations in trenchless pipeline rehabilitation.The improved mechanical properties meet the operational demands of underground pipes,suggesting practical applicability in trenchless pipeline repair.展开更多
Water hammer following the tripping of pumps can lead to overpressure and negative pressure. Reduction in overpressure and negative pressure may be necessary to avoid failure, to improve the efficiency of operation an...Water hammer following the tripping of pumps can lead to overpressure and negative pressure. Reduction in overpressure and negative pressure may be necessary to avoid failure, to improve the efficiency of operation and to avoid fatigue of system components. The field tests on the water hammer have been conducted on the pump rising pipeline system with an air chamber. The hydraulic transient was simulated using the method of characteristics. Minimizing the least squares problem representing the difference between the measured and predicted transient response in the system performs the calibration of the simulation program. Among the input variables used in the water hammer analysis, the polytropic exponent, the discharge coefficient and the wave speed were calibrated. The computer program developed in this study will be useful in designing the optimum parameters of an air chamber for the real pump pipeline system. The correct selection of air chamber size and the effect of the inner diameter of the orifice to minimize water hammer have been investigated by both field measurements and numerical modeling.展开更多
The batch transportation process of several kinds of crude oil is accomplished by an entire coupled pipeline system,which exhibits complex thermo-hydraulic characteristics.Based on the coupled characteristics among so...The batch transportation process of several kinds of crude oil is accomplished by an entire coupled pipeline system,which exhibits complex thermo-hydraulic characteristics.Based on the coupled characteristics among soil,pipelines and devices(including pumps,heating furnaces and valves),a coupled simulation model of batch transportation for the crude oil pipeline system is established,and a novel coupled simulation algorithm is proposed.The simulation results are in good agreement with the field data of an actual crude oil pipeline system.In addition,based on the numerical simulation,thermo-hydraulic characteristics of pipeline system are investigated,and some new thermo-hydraulic characteristics are obtained.In the batch transportation process with constant flowrate,the change trends of temperature at the outlet of each pipeline segment are hysteretic and the change ranges of temperature become small along mileage.And the adjustment of devices influences thermohydraulic characteristics to some extent.In the batch transportation process with variable flowrate,the complex thermo-hydraulic characteristics are exhibited,which are induced by the comprehensive influence of the changes of oil type,flowrate and absorbed/released heat.Compared with the transportation process with constant flowrate,the high-viscosity oil exhibits similar minimum temperature and lower maximum pressure in the transportation process with variable flowrate,which means that the higher transportation safety of pipeline system is obtained.This study can provide a scientific reference for making the safer batch transportation scheme of crude oil pipeline system.展开更多
In this paper,a novel systematic and integrated methodology to assess gas supply reliability is proposed based on the Monte Carlo method,statistical analysis,mathematical-probabilistic analysis,and hydraulic simulatio...In this paper,a novel systematic and integrated methodology to assess gas supply reliability is proposed based on the Monte Carlo method,statistical analysis,mathematical-probabilistic analysis,and hydraulic simulation.The method proposed has two stages.In the first stage,typical scenarios are determined.In the second stage,hydraulic simulation is conducted to calculate the flow rate in each typical scenario.The result of the gas pipeline system calculated is the average gas supply reliability in each typical scenario.To verify the feasibility,the method proposed is applied for a real natural gas pipelines network system.The comparison of the results calculated and the actual gas supply reliability based on the filed data in the evaluation period suggests the assessment results of the method proposed agree well with the filed data.Besides,the effect of different components on gas supply reliability is investigated,and the most critical component is identified.For example,the 48th unit is the most critical component for the SH terminal station,while the 119th typical scenario results in the most severe consequence which causes the loss of 175.61×10^4 m^3 gas when the 119th scenario happens.This paper provides a set of scientific and reasonable gas supply reliability indexes which can evaluate the gas supply reliability from two dimensions of quantity and time.展开更多
An automatic control technique for the flow regulation in pipeline systems is developed in the paper. The improvement for the previous work is the use of an optimal observer that reduces greatly the time of changing n...An automatic control technique for the flow regulation in pipeline systems is developed in the paper. The improvement for the previous work is the use of an optimal observer that reduces greatly the time of changing now states and the adaptability for the regulation of frictioness now. By first order Taylor-expanding the frictioness flow equations of motion and continuity at equilibrium states, a set of linear equations are obtained then, the linear quadratic design technique in automatic control theory is used to control the now states. In order to avoid measuring all states, an optimal state estimator is constructed. A pipeline system is taken as example. The regulation results are satisfactory. If the changes of discharges are within 20%, the method developed in this paper is effective for valve-motion synthesis in real pipeline systems.展开更多
基金The Fundamental Research Funds for the Central Universities(JD2423)。
文摘Pump valve pipeline vibration brings serious safety hazards to the operation of the equipment,for the pump valve system in the process of variable flow,variable speed,variable openings lead to excessive pipeline vibration.An active damping device(ADD)is used to the vibration of the pump valve pipeline system to apply the control force,to achieve the active control of the pipeline vibration.A pump-valve pipeline vibration test bench was built to compare the control effect of active damping device on pipeline vibration under different pump valve working conditions,and the results show that applying ADD control could effectively suppress the vibration of the pump valve pipeline and enhance the stability of the equipment during operation.At different pump operating rotation frequencies,the vibration amplitude of the pump valve pipeline in working frequency and its multiple frequencies are also effectively suppressed,with the maximum amplitude reduction of more than 60%.For the valve vibration caused by different operating openings,the vibration of the highest reduction of 68%,and the centrifugal pump drive shaft vi-bration reduced by up to 73%,which provides a new idea for vibration control of pump valve pipeline system.
基金Supported by National Natural Science Foundation of China(Grant No.51875460)Aviation Power Foundation(Grant No.6141B090320)Foundation of Innovation and Creation for Graduate Students in Northwestern Ploytechnical University(Grant No.ZZ2019124).
文摘The design of aircraft hydraulic pipeline system is limited by many factors,such as the integrity of aviation structure or narrow installation space,so the limited clamp support position should be considered.This paper studied the frequency adjustment and dynamic responses reduction of the multi-support pipeline system through experiment and numerical simulation.To avoid the resonance of pipeline system,we proposed two different optimization programs,one was to avoid aero-engine working range,and another was to avoid aircraft hydraulic pump pulsation range.An optimization method was introduced in this paper to obtain the optimal clamp position.The experiments were introduced to validate the optimization results,and the theoretical optimization results can agree well with the test.With regard to avoiding the aero-engine vibration frequency,the test results revealed that the first natural frequency was far from the aero-engine vibration frequency.And the dynamic frequency sweep results showed that no resonance occurred on the pipeline in the engine vibration frequency range after optimization.Additionally,with regard to avoiding the pump vibration frequency,the test results revealed that natural frequencies have been adjusted and far from the pump vibration frequency.And the dynamic frequency sweep results showed that pipeline under optimal clamp position cannot lead to resonance.The sensitivity analysis results revealed the changing relationships between different clamp position and natural frequency.This study can provide helpful guidance on the analysis and design of practical aircraft pipeline.
文摘Gases have long been used for medical applications across the world. Medical oxygen, one of the most important medical gases, has been widely applied both in hospitals and at home. It is defined as a drug and its pipeline distribution systems are medical devices whose quality and management should conform to specific standards. In China, several deficiencies relating to the distribution and use of medical oxygen, which may lead to a number of fatal accidents like gas pipeline explosion and cause illicit product use, have been revealed in health facilities. They are the result of a lack of the relevant standards, management and practical experiences. To overcome these failures, it might be interesting to refer to the experience and regulations of other countries, for example, those of France.
文摘Classical beat phenomenon has been observed in most combined systems. The focus of this paper is to provide a better understanding of this phenomenon in an offshore pile-supported pipeline system. The beat phenomeon is caused by the coupling movement of the pipeline and its vertical pile support under certain conditions. It can induce excessive vibration and cause fatigue failure at pipe elbow. However, in some circumstances it does not exist. Numerical results in both frequency and time domains are presented to elucidate this phenomenon in a combined pipeline system. The conclusions of this paper could give constructive guidance to future design of simply supported pipeline systems.
基金the National Natural Science Foundation of China(No.51805462)。
文摘Vibrations in aircraft hydraulic pipeline system,due to multi-source excitation of high fluid pressure fluctuation and serious vibration environment of airframe,can cause the pipeline system vibration failures through overload in engineering field.Controlling the vibrations in hydraulic pipeline is a challenging work to ensure the flight safety of aircraft.The common vibration control technologies have been demonstrated to be effective in typical structures such as aerospace structures,shipbuilding structures,marine offshore structures,motor structures,etc.However,there are few research literatures on vibration control strategies of aircraft hydraulic pipeline.Combining with the development trend of aircraft hydraulic pipeline system and the requirement of vibration control technologies,this paper provides a detailed review on the current vibration control technologies in hydraulic pipeline system.A review of the general approaches following the passive and active control technologies are presented,which are including optimal layout technique of pipeline and clamps,constrained layer damping technique,vibration absorber technique,hydraulic hose technique,optimal pump structure technique,and active vibration control technique of pipeline system.Finally,some suggestions for the application of vibration control technologies in engineering field are given.
基金supported by National Natural Science Foundation of China(No.11772089)Fundamental Research Funds for the Central Universities(Nos.N170308028,N170306004 and N180708009)Program for the Innovative Talents of Higher Learning Institutions of Liaoning(LR2017035)。
文摘There exists a lot of research on the nonlinear vibration of the pipeline system with different boundary conditions.To the best of our knowledge,little research on the actual constraint of the clamp has been performed.In this paper,according to hysteresis loops of the clamp obtained from experimental test,the simplified bilinear stiffness and damping model is proposed.Then the Finite Element(FE)model of L-type pipeline system with clamps is established using Timoshenko beam theory in combination with aforementioned stiffness-damping model.Both hammering and shaker tests verify the FE model via the comparisons of natural frequencies and vibration responses.The results show that the maximum errors of natural frequencies and vibration responses are about 8.31%and 17.6%,respectively.The proposed model can simulate the dynamic characteristics of the L-type pipeline system with clamps well,which is helpful to provide some guidance for the early design stage of pipeline in aero-engine.
基金supported by the National Natural Science Foundation of China(Nos.51975025 and 51890822)the Young Elite Scientists Sponsorship Program by China Association for Science and Technology(No.2016QNRC001)the National Key Research and Development Program of China(No.2019YFB2004500)。
文摘The fluid-structure interaction(FSI)in aircraft hydraulic pipeline systems is of great concern because of the damage it causes.To accurately predict the vibration characteristic of long hydraulic pipelines with curved segments,we studied the frequency-domain modeling and solution method for FSI in these pipeline systems.Fourteen partial differential equations(PDEs)are utilized to model the pipeline FSI,considering both frequency-dependent friction and bending-flexibility modification.To address the numerical instability encountered by the traditional transfer matrix method(TMM)in solving relatively complex pipelines,an improved TMM is proposed for solving the PDEs in the frequency domain,based on the matrix-stacking strategy and matrix representation of boundary conditions.The proposed FSI model and improved solution method are validated by numerical cases and experiments.An experimental rig of a practical hydraulic system,consisting of an aircraft engine-driven pump,a Z-shaped aero-hydraulic pipeline,and a throttle valve,was constructed for testing.The magnitude ratio of acceleration to pressure is introduced to evaluate the theoretical and experimental results,which indicate that the proposed model and solution method are effective in practical applications.The methodology presented in this paper can be used as an efficient approach for the vibrational design of aircraft hydraulic pipeline systems.
基金supported by the National Scientific and Technological support project MST (2006BAC13B02-0106)spe-cial research funds from the Public Institute of China,Institute of Geophysics (IGP),China Earthquake Ad-ministration (CEA) (DQJB06A01)The contribution No. is 10FE3004,IGP,CEA
文摘The purpose of this paper is to adopt the uniform confidence method in both water pipeline design and oil-gas pipeline design.Based on the importance of pipeline and consequence of its failure,oil and gas pipeline can be classified into three pipe classes,with exceeding probabilities over 50 years of 2%,5% and 10%,respectively.Performance-based design requires more information about ground motion,which should be obtained by evaluating seismic safety for pipeline engineering site.Different from a city＇s water pipeline network,the long-distance oil and gas pipeline system is a spatially linearly distributed system.For the uniform confidence of seismic safety,a long-distance oil and pipeline formed with pump stations and different-class pipe segments should be considered as a whole system when analyzing seismic risk.Considering the uncertainty of earthquake magnitude,the design-basis fault displacements corresponding to the different pipeline classes are proposed to improve deterministic seismic hazard analysis（DSHA）.A new empirical relationship between the maximum fault displacement and the surface-wave magnitude is obtained with the supplemented earthquake data in East Asia.The estimation of fault displacement for a refined oil pipeline in Wenchuan MS8.0 earthquake is introduced as an example in this paper.
基金The National Natural Science Foundation of China under contract Nos 42106198 and 41720104001the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)under contract No.GML2019ZD0210.
文摘The ever-increasing deepwater oil and gas development in the Qiongdongnan Basin,South China Sea has initiated the need to evaluate submarine debris-flow hazard risks to seafloor infrastructures.This paper presents a case study on evaluating the debris-flow hazard risks to the planned pipeline systems in this region.We used a numerical model to perform simulations to support this quantitative evaluation.First,one relict failure interpreted across the development site was simulated.The back-analysis modeling was used to validate the applicability of the rheological parameters.Then,this model was applied to forecast the runout behaviors of future debris flows originating from the unstable upslope regions considered to be the most critical to the pipeline systems surrounding the Manifolds A and B.The model results showed that the potential debris-flow hazard risks rely on the location of structures and the selection of rheological parameters.For the Manifold B and connected pipeline systems,because of their remote distances away from unstable canyon flanks,the potential debris flows impose few risks.However,the pipeline systems around the Manifold A are exposed to significant hazard risks from future debris flows with selected rheological parameters.These results are beneficial for the design of a more resilient pipeline route in consideration of future debris-flow hazard risks.
文摘Losses due to hazards are inevitable and numerical simulations for estimations are complex.This study proposes a model for estimating correlated seismic damages and losses of a water supply pipeline system as an alternative for numerical simulations.The common approach in other research shows average damage spots per mesh estimated statistically independent to one another.Spatially distributed lifeline systems,such as water supply pipelines,are interconnected,and seismic spatial variability affects the damages across the region;thus,spatial correlation of damage spots is an important factor in target areas for portfolio loss estimation.Generally,simulations are used to estimate possible losses;however,these assume each damage behaves independently and uncorrelated.This paper assumed that damages per mesh behave in a Poisson distribution to avoid over-dispersion and eliminate negative losses in estimations.The purpose of this study is to obtain a probabilistic portfolio loss model of an extensive water supply area.The proposed model was compared to the numerical simulation data with the correlated Poisson distribution.The application of the Normal To Anything(NORTA)obtained correlations for Poisson Distributions.The proposed probabilistic portfolio loss model,based on the generalized linear model and central limit theory,estimated the possible losses,such as the Probable Maximum Loss(PML,90%non-exceedance)or Normal Expected Loss(NEL,50%non-exceedance).The proposed model can be used in other lifeline systems as well,though additional investigation is needed for confirmation.From the estimations,a seismic physical portfolio loss for the water supply system was presented.The portfolio was made to show possible outcomes for the system.The proposed method was tested and analyzed using an artificial field and a location-based scenario of a water supply pipeline system.This would aid in pre-disaster planning and would require only a few steps and time.
基金This work is supported by Natural Science Foundation of Shandong Province(Grant no.ZR2018MEE021)Equipment Pre Research Fund Project(Grant no.61402100501).
文摘When designing a complex pipeline with long distance and multi-supports for offshore platform,it is necessary to analyze the vibration characteristics of the complex pipeline system to ensure that there is no harmful resonance in the working conditions.Therefore,the optimal layout of support is an effective method to reduce the vibration response of hydraulic pipeline system.In this paper,a developed dynamic optimization method for the complex pipeline is proposed to investigate the vibration characteristics of complex pipeline with multi-elastic supports.In this method,the Kriging response surface model between the support position and pipeline is established.The position of the clamp in the model is parameterized and the optimal solution of performance index is obtained by genetic algorithm.The number of clamps and the interval between clamps are considered as the constraints of layout optimization,and the optimization objective is the natural frequencies of pipeline.Taking a typical offshore pipeline as example to demonstrate the effectiveness of the proposed method,the results show that the vibration performance of the hydraulic pipeline system is distinctly improved by the optimization procedure,which can provide reasonable guidance for the design of complex hydraulic pipeline system.
文摘This work focuses on the development and implementation of a simulation-based approach for the detection of partial and extended blockages within an edible oil pipeline system. Blockages, whether partial or extended, pose a significant operational and safety risks. This study employs computational fluid dynamics (CFD) simulations to model the flow behaviour of edible oil through pipeline under varying conditions. It leverages advanced computational fluid dynamics (CFD) simulations to analyze pressure, velocity, and temperature variations along the pipeline. By simulating scenarios with different blockage characteristics, there is establishment of distinctive patterns indicative of partial and extended obstructions. Through extensive analysis of simulation data, sensing element, and monitoring system, processing signal input and response output, the system can accurately pinpoint the location and severity of blockages, providing crucial insights for timely intervention. The detection system represents a significant advancement in pipeline monitoring technology, offering a proactive and accurate approach to identify blockages and mitigate potential risks and ensure the uninterrupted flow of edible oil, thereby enabling timely intervention and maintenance.
基金The Petroleum Training Development Fund(PTDF)is highly acknowledged for sponsorship.
文摘The global discussion surrounding Functionally Graded Materials(FGMs)highlights their unique and diverse micro-material properties that result from varying two or more materials in a strategic combination profile.These combinations produce distinct physical and chemical characteristics.Changes in these characteristics may occur continuously,referred to as a gradient function,or discontinuously as a stepwise function.The changes can appear within homogeneous or heterogeneous material geometries.The variation in material properties depends on the volume fraction index function.This variation can occur in 1D,2D,or 3D,either in the thickness or length direction within a material model.The vacuum in the review study on mechanically toughened and thermally resistant Functionally Graded(FG)pipelines prompted the current review study.This study addresses the absence of an appropriate variational function for FG cylindrical pipelines.It proposes a gradation function pattern to improve pipeline structural performance.An appraisal based on relevant FGM literature was conducted to improve the temperature differentials in traditional composite materials and stress-related issues in carbon steel pipelines.The review identifies specific FGM property variations that reduce failures that are possible in conventional materials.Reviewed articles and evaluation procedures followed the 2020 PRISMA guidelines.Literature was obtained from Scopus,Connected Papers,and other reputable sources.The study also discusses potential FG pipelines for gas and green energy transportation.The reviewed literature establishes the context for this research and addresses the gap in 3D FG model variation functions involving multiple materials.
文摘This article focuses on the optimization of water supply and drainage systems,involving theories such as hydraulic models of pipeline systems and multi-objective collaborative optimization.It introduces the system dynamics model of sewage treatment facility expansion.Elaborating on detection technology,construction of an intelligent operation and maintenance system,and factors to be considered for sewage plant expansion,it emphasizes the importance of collaborative development and verifies benefits through the PSR model.
基金Funded by the National Natural Science Foundation of China(No.52473077)China Three Gorges Corporation(No.202403190)。
文摘In ultraviolet cured-in-place-pipe(UV-CIPP)pipeline rehabilitation,resin performance critically determines repair effectiveness.Current UV-curable resins exhibit high volatile organic compound(VOC)emissions and inadequate post-cure toughness,which compromise fatigue resistance during service.To address these issues,we synthesized hydroxyl-terminated polyurethane acrylate prepolymers using diphenylmethane diisocyanate(MDI),polypropylene glycol(PPG),and hydroxyethyl methacrylate(HEMA).Fourier transform infrared spectroscopy(FTIR)confirmed successful prepolymer synthesis.We developed UV-curable resins by incorporating various crosslinking monomers and optimized the formulations through mechanical property analysis.Testing revealed that the polyurethane-acrylic UV-cured resin system combines polyurethane's mechanical excellence with acrylics'high UV-curing activity.The PPG200/MDI/HEMA formulation achieved superior performance,with a tensile strength of 55.31 MPa,an impact toughness of 22.7 kJ/m^(2),and a heat deflection temperature(HDT)of 132℃.The optimized system eliminates volatile components while maintaining high reactivity,addressing critical limitations in trenchless pipeline rehabilitation.The improved mechanical properties meet the operational demands of underground pipes,suggesting practical applicability in trenchless pipeline repair.
文摘Water hammer following the tripping of pumps can lead to overpressure and negative pressure. Reduction in overpressure and negative pressure may be necessary to avoid failure, to improve the efficiency of operation and to avoid fatigue of system components. The field tests on the water hammer have been conducted on the pump rising pipeline system with an air chamber. The hydraulic transient was simulated using the method of characteristics. Minimizing the least squares problem representing the difference between the measured and predicted transient response in the system performs the calibration of the simulation program. Among the input variables used in the water hammer analysis, the polytropic exponent, the discharge coefficient and the wave speed were calibrated. The computer program developed in this study will be useful in designing the optimum parameters of an air chamber for the real pump pipeline system. The correct selection of air chamber size and the effect of the inner diameter of the orifice to minimize water hammer have been investigated by both field measurements and numerical modeling.
基金supported by the fund of the Beijing Municipal Education Commission(No.22019821001)Award Cultivation Foundation from Beijing Institute of Petrochemical Technology(No.BIPTACF-002)。
文摘The batch transportation process of several kinds of crude oil is accomplished by an entire coupled pipeline system,which exhibits complex thermo-hydraulic characteristics.Based on the coupled characteristics among soil,pipelines and devices(including pumps,heating furnaces and valves),a coupled simulation model of batch transportation for the crude oil pipeline system is established,and a novel coupled simulation algorithm is proposed.The simulation results are in good agreement with the field data of an actual crude oil pipeline system.In addition,based on the numerical simulation,thermo-hydraulic characteristics of pipeline system are investigated,and some new thermo-hydraulic characteristics are obtained.In the batch transportation process with constant flowrate,the change trends of temperature at the outlet of each pipeline segment are hysteretic and the change ranges of temperature become small along mileage.And the adjustment of devices influences thermohydraulic characteristics to some extent.In the batch transportation process with variable flowrate,the complex thermo-hydraulic characteristics are exhibited,which are induced by the comprehensive influence of the changes of oil type,flowrate and absorbed/released heat.Compared with the transportation process with constant flowrate,the high-viscosity oil exhibits similar minimum temperature and lower maximum pressure in the transportation process with variable flowrate,which means that the higher transportation safety of pipeline system is obtained.This study can provide a scientific reference for making the safer batch transportation scheme of crude oil pipeline system.
文摘In this paper,a novel systematic and integrated methodology to assess gas supply reliability is proposed based on the Monte Carlo method,statistical analysis,mathematical-probabilistic analysis,and hydraulic simulation.The method proposed has two stages.In the first stage,typical scenarios are determined.In the second stage,hydraulic simulation is conducted to calculate the flow rate in each typical scenario.The result of the gas pipeline system calculated is the average gas supply reliability in each typical scenario.To verify the feasibility,the method proposed is applied for a real natural gas pipelines network system.The comparison of the results calculated and the actual gas supply reliability based on the filed data in the evaluation period suggests the assessment results of the method proposed agree well with the filed data.Besides,the effect of different components on gas supply reliability is investigated,and the most critical component is identified.For example,the 48th unit is the most critical component for the SH terminal station,while the 119th typical scenario results in the most severe consequence which causes the loss of 175.61×10^4 m^3 gas when the 119th scenario happens.This paper provides a set of scientific and reasonable gas supply reliability indexes which can evaluate the gas supply reliability from two dimensions of quantity and time.
文摘An automatic control technique for the flow regulation in pipeline systems is developed in the paper. The improvement for the previous work is the use of an optimal observer that reduces greatly the time of changing now states and the adaptability for the regulation of frictioness now. By first order Taylor-expanding the frictioness flow equations of motion and continuity at equilibrium states, a set of linear equations are obtained then, the linear quadratic design technique in automatic control theory is used to control the now states. In order to avoid measuring all states, an optimal state estimator is constructed. A pipeline system is taken as example. The regulation results are satisfactory. If the changes of discharges are within 20%, the method developed in this paper is effective for valve-motion synthesis in real pipeline systems.
