This paper reviews the dynamics of ocean pipes aspirating fluid and presents a selective review of the research undertaken on it. It focuses on the equations of motion, fluid-solid interaction at the inlet of the free...This paper reviews the dynamics of ocean pipes aspirating fluid and presents a selective review of the research undertaken on it. It focuses on the equations of motion, fluid-solid interaction at the inlet of the free end of the pipe, the stability mechanism of pipes aspirating steady fluid, etc. In particular, some unresolved or partly resolved issues on these important aspects are discussed. Finally, the promising future development in this area is discussed.展开更多
A double perturbation strategy is presented to solve the asymptotic solutions of a Johnson-Segalman （J-S） fluid through a slowly varying pipe. First, a small parameter of the slowly varying angle is taken as the sma...A double perturbation strategy is presented to solve the asymptotic solutions of a Johnson-Segalman （J-S） fluid through a slowly varying pipe. First, a small parameter of the slowly varying angle is taken as the small perturbation parameter, and then the second-order asymptotic solution of the flow of a Newtonian fluid through a slowly varying pipe is obtained in the first perturbation strategy. Second, the viscoelastic parameter is selected as the small perturbation parameter in the second perturbation strategy to solve the asymptotic solution of the flow of a J-S fluid through a slowly varying pipe. Finally, the parameter effects, including the axial distance, the slowly varying angle, and the Reynolds number, on the velocity distributions are analyzed. The results show that the increases in both the axial distance and the slowly varying angle make the axial velocity slow down. However, the radial velocity increases with the slowly varying angle, and decreases with the axial distance. There are two special positions in the distribution curves of the axial velocity and the radial velocity with different Reynolds numbers, and there are different trends on both sides of the special positions. The double perturbation strategy is applicable to such problems with the flow of a non-Newtonian fluid through a slowly varying pipe.展开更多
In the shipbuilding industry,market competition is currently operating in an intense state.To be able to strive in the global market,the shipbuilders must able to produce ships that are more efficient and can be const...In the shipbuilding industry,market competition is currently operating in an intense state.To be able to strive in the global market,the shipbuilders must able to produce ships that are more efficient and can be constructed in a relatively short amount of time.The piping layouts in the engine room requires a lot of time for the designer to design the best possible route and in a way are not the most efficient route.This paper presents an automatic piping support system in the ship’s engine room based on the Dijkstra’s algorithm of pathfinding method.The proposed method is focused on finding the shortest possible route with a consideration of the following things:cost of the bend pipe,cost of the crossing pipe,cost reduction by pipe support,restriction on piping,reduction of calculation time,and design procedure of piping route.Dijkstra’s shortest path algorithm is adopted to find the shortest path route between the start and goal point that is determined based on the layout of the ship’s engine room.Genetic algorithm is adopted to decide the sequence of the pipe execution.The details of the proposed method are explained in this paper.This paper also discusses the application of the proposed method on an actual ship and evaluates its effectiveness.展开更多
Based on Hencky＇s total strain theory of plasticity,ultimate bending capacity of steel pipes can be determined analytically assuming an elastic-linear strain hardening material,the simplified analytical solution is p...Based on Hencky＇s total strain theory of plasticity,ultimate bending capacity of steel pipes can be determined analytically assuming an elastic-linear strain hardening material,the simplified analytical solution is proposed as well.Good agreement is observed when ultimate bending capacities obtained from analytical solutions are compared with experimental results from full-size tests of steel pipes.Parametric study conducted as part of this paper indicates that the strain hardening effect has significant influence on the ultimate bending capacity of steel pipes.It is shown that pipe considering strain hardening yields higher bending capacity than that of pipe assumed as elastic-perfectly plastic material.Thus,the ignorance of strain hardening effect,as commonly assumed in current codes,may underestimate the ultimate bending capacity of steel pipes.The solutions proposed in this paper are applicable in the design of offshore/onshore steel pipes,supports of offshore platforms and other tubular structural steel members.展开更多
The corrosion mechanism of the S135 drill pipes was investigated through observation of the corrosion morphology and analysis of the corrosion products by scanning electronic microscope （ SEM）, energy dispersive spe...The corrosion mechanism of the S135 drill pipes was investigated through observation of the corrosion morphology and analysis of the corrosion products by scanning electronic microscope （ SEM）, energy dispersive spectrum （EDS） and X-ray diffraction （XRD）. The results show that the localized corrosion on the outer surface of the drill pipes was caused by oxygen corrosion due to the action of retained slurry. Cl - contained in slurry accelerated the corrosion and promoted the development of corrosion pits. Suggestions for mitigating or preventing such corrosion of the drill pipes are proposed based on the research results.展开更多
This article shows an innovative method to model and validate the hot air flow through the blast furnacés tuyeres. This study will be the basis for flow measurements implementation and safety interlocks for the p...This article shows an innovative method to model and validate the hot air flow through the blast furnacés tuyeres. This study will be the basis for flow measurements implementation and safety interlocks for the pulverized coal injection. The flow measurements were taken in the blast furnace down leg pipes by installing refractory Venturi tubes. The system for the calculation of differential pressure takes into consideration the dimension of the Venturi, the air density and compressibility. The objective is to specify the flow transmitters required to automate a control system and implement safety interlocks for the coal injection plant.展开更多
YANDAI Xiejie,or Tobacco Pipe Oblique Street,lies north of Di’anmen(Gate of Earthly Peace) and in front of the Drum Tower.It’s the oldest street of its kind in Beijing.Running northeast to southwest, the 232-meter-l...YANDAI Xiejie,or Tobacco Pipe Oblique Street,lies north of Di’anmen(Gate of Earthly Peace) and in front of the Drum Tower.It’s the oldest street of its kind in Beijing.Running northeast to southwest, the 232-meter-long lane is shaped like the stem of a tobacco pipe.The pipe’s mouthpiece is at the street’s eastern entrance, while the western part turning south toward Yinding Bridge(Silver Ingot Bridge) appears to look like a pipe bowl,hence Yandai Xiejie’s name.展开更多
基金The workis supported bythe National Natural Science Foundation of China (Grant No.10772071)the ScienceInvestigation Foundtion of HUST(Grant No.2006Q003B)
文摘This paper reviews the dynamics of ocean pipes aspirating fluid and presents a selective review of the research undertaken on it. It focuses on the equations of motion, fluid-solid interaction at the inlet of the free end of the pipe, the stability mechanism of pipes aspirating steady fluid, etc. In particular, some unresolved or partly resolved issues on these important aspects are discussed. Finally, the promising future development in this area is discussed.
基金supported by the National Natural Science Foundation of China(Nos.11572203 and11332006)
文摘A double perturbation strategy is presented to solve the asymptotic solutions of a Johnson-Segalman （J-S） fluid through a slowly varying pipe. First, a small parameter of the slowly varying angle is taken as the small perturbation parameter, and then the second-order asymptotic solution of the flow of a Newtonian fluid through a slowly varying pipe is obtained in the first perturbation strategy. Second, the viscoelastic parameter is selected as the small perturbation parameter in the second perturbation strategy to solve the asymptotic solution of the flow of a J-S fluid through a slowly varying pipe. Finally, the parameter effects, including the axial distance, the slowly varying angle, and the Reynolds number, on the velocity distributions are analyzed. The results show that the increases in both the axial distance and the slowly varying angle make the axial velocity slow down. However, the radial velocity increases with the slowly varying angle, and decreases with the axial distance. There are two special positions in the distribution curves of the axial velocity and the radial velocity with different Reynolds numbers, and there are different trends on both sides of the special positions. The double perturbation strategy is applicable to such problems with the flow of a non-Newtonian fluid through a slowly varying pipe.
基金supported the Directorate of Research and Community Engagement,Universitas Indonesia,and scheme of Research Collaboration,contract number:NKB-1954/UN2.R3.1/HKP.05.00/2019.
文摘In the shipbuilding industry,market competition is currently operating in an intense state.To be able to strive in the global market,the shipbuilders must able to produce ships that are more efficient and can be constructed in a relatively short amount of time.The piping layouts in the engine room requires a lot of time for the designer to design the best possible route and in a way are not the most efficient route.This paper presents an automatic piping support system in the ship’s engine room based on the Dijkstra’s algorithm of pathfinding method.The proposed method is focused on finding the shortest possible route with a consideration of the following things:cost of the bend pipe,cost of the crossing pipe,cost reduction by pipe support,restriction on piping,reduction of calculation time,and design procedure of piping route.Dijkstra’s shortest path algorithm is adopted to find the shortest path route between the start and goal point that is determined based on the layout of the ship’s engine room.Genetic algorithm is adopted to decide the sequence of the pipe execution.The details of the proposed method are explained in this paper.This paper also discusses the application of the proposed method on an actual ship and evaluates its effectiveness.
基金financially supported by the National Natural Science Foundation of China(Grant No.51309236)the Opening Fund of State Key Laboratory of Ocean Engineering(Shanghai Jiao Tong University)(Grant No.1314)+2 种基金the Opening Fund of State Key Laboratory of Hydraulic Engineering Simulation and Safety(Tianjin University)(Grant No HESS-1411)the Opening Fund of State Key Laboratory of Coastal and Offshore Engineering(Dalian University of Technology)(Grant No.LP1507)the Science Foundation of China University of Petroleum,Beijing(Grant Nos.2462015YQ0403 and 2462015YQ0408)
文摘Based on Hencky＇s total strain theory of plasticity,ultimate bending capacity of steel pipes can be determined analytically assuming an elastic-linear strain hardening material,the simplified analytical solution is proposed as well.Good agreement is observed when ultimate bending capacities obtained from analytical solutions are compared with experimental results from full-size tests of steel pipes.Parametric study conducted as part of this paper indicates that the strain hardening effect has significant influence on the ultimate bending capacity of steel pipes.It is shown that pipe considering strain hardening yields higher bending capacity than that of pipe assumed as elastic-perfectly plastic material.Thus,the ignorance of strain hardening effect,as commonly assumed in current codes,may underestimate the ultimate bending capacity of steel pipes.The solutions proposed in this paper are applicable in the design of offshore/onshore steel pipes,supports of offshore platforms and other tubular structural steel members.
文摘The corrosion mechanism of the S135 drill pipes was investigated through observation of the corrosion morphology and analysis of the corrosion products by scanning electronic microscope （ SEM）, energy dispersive spectrum （EDS） and X-ray diffraction （XRD）. The results show that the localized corrosion on the outer surface of the drill pipes was caused by oxygen corrosion due to the action of retained slurry. Cl - contained in slurry accelerated the corrosion and promoted the development of corrosion pits. Suggestions for mitigating or preventing such corrosion of the drill pipes are proposed based on the research results.
文摘This article shows an innovative method to model and validate the hot air flow through the blast furnacés tuyeres. This study will be the basis for flow measurements implementation and safety interlocks for the pulverized coal injection. The flow measurements were taken in the blast furnace down leg pipes by installing refractory Venturi tubes. The system for the calculation of differential pressure takes into consideration the dimension of the Venturi, the air density and compressibility. The objective is to specify the flow transmitters required to automate a control system and implement safety interlocks for the coal injection plant.
文摘YANDAI Xiejie,or Tobacco Pipe Oblique Street,lies north of Di’anmen(Gate of Earthly Peace) and in front of the Drum Tower.It’s the oldest street of its kind in Beijing.Running northeast to southwest, the 232-meter-long lane is shaped like the stem of a tobacco pipe.The pipe’s mouthpiece is at the street’s eastern entrance, while the western part turning south toward Yinding Bridge(Silver Ingot Bridge) appears to look like a pipe bowl,hence Yandai Xiejie’s name.
