scholarly journals Development of a Practical and High Accuracy Simulation Technique based on Numerical Modal Approximation for Fluid Transients in Compound Pipeline Systems. 1st Report. Establishment of Fundamental Calculation Algorithm.

2002 ◽  
Vol 33 (2) ◽  
pp. 48-56 ◽  
Author(s):  
Masaaki SHINADA ◽  
Eiichi KOJIMA
Keyword(s):  
High Accuracy ◽  
Simulation Technique ◽  
Calculation Algorithm ◽  
Pipeline Systems ◽  
Fluid Transients ◽  
Modal Approximation

Development of a New Simulation Technique Based on the Modal Approximation for Fluid Transients in Complex Pipeline Systems With Time-Variant Nonlinear Boundary Conditions

2006 ◽  
Vol 129 (6) ◽  
pp. 791-798 ◽  
Author(s):  
E. Kojima ◽  
T. Yamazaki ◽  
M. Shinada
Keyword(s):  
Boundary Conditions ◽  
Nonlinear Boundary ◽  
Safety Valve ◽  
Nonlinear Boundary Conditions ◽  
Simulation Technique ◽  
Nonlinear Relationship ◽  
Calculation Methods ◽  
Pipeline Systems ◽  
Fluid Transients ◽  
Modal Approximation

A new simulation technique called the system modal approximation method (SMA) for fluid transients in complex pipeline systems has been proposed. The superiority of this technique compared to other existing methods has been verified. Thus far, however, detailed considerations have been limited to pipelines having elementary boundary conditions. In the present paper, for the generalization of the SMA method, calculation methods are newly proposed for the case in which the boundary conditions are given by the time-variant nonlinear relationship between pressure and flow rate, such as the conditions in a safety valve, and its usefulness is verified by comparison to experimental measurements.

scholarly journals Development of a New Bi-Arc Dynamic Numerical Model for Modeling AC Flashover Processes of EHV Ice-Covered Insulators

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2792
Author(s):  
Marouane Jabbari ◽  
Christophe Volat ◽  
Issouf Fofana
Keyword(s):  
Numerical Model ◽  
High Accuracy ◽  
Arc Length ◽  
Calculation Algorithm ◽  
Water Conductivity ◽  
Arc Model ◽  
Proposed Model ◽  
Flashover Voltage ◽  
Extra High Voltage ◽  
Future Work

This paper presents the development of a new bi-arc dynamic numerical model for predicting AC critical flashover voltage (FOV) of ice-covered extra-high voltage (EHV) insulators. The proposed model is based on a generic calculation algorithm coupled with commercial finite element method software designed to solve the Obenaus/Rizk model. The proposed model allows one to implement the Nottingham and Mayr approaches and compare the results obtained as a function of the arcing distance, the freezing water conductivity, and the initial arc length. The validation of the model demonstrated high accuracy in predicting the FOV of ice-covered post-type insulators and its capability to simulate the interaction of the two partial arcs during the flashover process. In particular, the results showed that the Nottingham approach is sensibly more accurate than the Mayr one, especially in simulating the dynamic behavior of the partial arcs during the flashover process. Based on the encouraging results obtained, a multi-arc calculation algorithm was proposed using the bi-arc dynamic numerical model as a basis. The basic idea, which consists in dividing the multi-arc model in several bi-arc modules, was not implemented and validated but will serve as a promising concept for future work.

Measurement of Vehicle Tire Footprint Pattern and Pressure Distribution Using Piezoresistive Force Sensor Mat and Image Analysis

2010 ◽  
Vol 437 ◽  
pp. 467-471 ◽  
Author(s):  
Rong Sheng Lu ◽  
Ning Liu ◽  
Xiao Huai Chen
Keyword(s):  
Image Processing ◽  
Image Analysis ◽  
Pressure Distribution ◽  
Digital Image Processing ◽  
Force Sensor ◽  
High Accuracy ◽  
Envelope Curve ◽  
Calculation Algorithm ◽  
Measurement Principle ◽  
Novel Method

In this paper, a novel method to measure the footprint pattern of a vehicle tire and its pressure distribution will be put forward. The measurement principle will be presented. The automatic digital image processing methods of the footprint pattern and pressure distribution images, which are used to characterize the footprint pattern, are described. Especially, a novel envelope curve calculation algorithm for finding a pattern boundary is introduced. The experimental results have shown that the methods mentioned in the paper are of robustness and high accuracy.

SENARIET, A Water Hammer Software for Analyzing Hydraulic Transients in Complex Circuits

2011 ◽  
Author(s):  
Marta Vargas-Mun˜oz ◽  
Manuel Rodri´guez-Ferna´ndez ◽  
A´ngel Peren˜a-Tapiador
Keyword(s):  
Safety Issue ◽  
Propagation Speed ◽  
Water Hammer ◽  
Pressure Waves ◽  
Pipeline Systems ◽  
Travelling Time ◽  
Fluid Transients ◽  
Complex Circuits ◽  
Compressibility Effects ◽  
Circuit Length

Water hammer transients are a danger for piping integrity and represent an important safety issue. In the design of pipeline systems it is necessary to take into account the magnitudes of pressure waves associated with water hammer phenomena and, therefore, it is important that these water hammer effects are calculated with the appropriate accuracy. SENARIET is a programme to study fluid transients in pipeline systems to obtain pressure and velocity distributions along a circuit. When a transient process occurs in periods of the same order of the pressure waves’ travelling time along a circuit (the order of the circuit length divided by the effective propagation speed), the compressibility effects in liquids have to be considered. Taking this effect into account, the appropriate equations of continuity and momentum are solved by the method of characteristics, to obtain pressure and velocity along pipes as a function of time. The programme considers different devices that usually take part in complex circuits, such as pumps, motorized valves, check valves, elbows, change of sections, bifurcations, vacuum valves, damping devices, reservoirs, etc. The simulated results have been compared to theoretical and experimental ones to validate and evaluate the precision of the software. The results help to perform efficient and accurate predictions in order to define the pipelines.

scholarly journals Information model of registration and analysis of technological factors arising during final processing of products of transport pipeline systems

2018 ◽  
Vol 7 (2.23) ◽  
pp. 73
Author(s):  
Volodimir Kotukh ◽  
Nataliy Kaptsova ◽  
Yuriy Pakhomov ◽  
Vitaliy Kosenko
Keyword(s):  
Production Process ◽  
Information Model ◽  
High Accuracy ◽  
Process Equipment ◽  
Technological Equipment ◽  
Technological Factors ◽  
Technological Characteristics ◽  
Pipeline Systems ◽  
Pipe Fittings ◽  
Working Bodies

One of the most important technological characteristics of the rubbing surfaces of the shut-off part of the pipe fittings (PF) of the transport pipeline systems (TPS) is their waviness, which is characterized by the deviation of the step of the wave to the height of the micro-roughness. The nature of the waviness is associated with oscillations of the working bodies of the executive devices of the technological equipment in the production process of manufacturing or repairing precision pairs of PF. The waviness of the rubbing surfaces of the PF shut-off part, as well as the high accuracy of their processing, is achieved by increasing the kinematic stiffness of the process equipment, as well as improving the methods and means for the precise processing of the PF precision pairs.  

Calculation Approach of Optimum Cutting Surfaces of Extra Length of Pipe Spools

2013 ◽  
Author(s):  
Takashi Kitahara ◽  
Yuichi Yamamoto ◽  
Yasutaka Tagawa
Keyword(s):  
Power Plant ◽  
Geometric Analysis ◽  
Three Dimensional ◽  
High Accuracy ◽  
Modeling Method ◽  
Construction Site ◽  
Calculation Algorithm ◽  
Dimensional Measurement ◽  
Optimum Cutting ◽  
Three Dimensional Measurement

To connect a pipe spool between existing pipes with high accuracy for power plant constructions, a calculation approach which figures out appropriate cutting positions and angles of extra length areas of the spool has been developed. In this approach, center positions and axes of end surfaces are modeled numerically based on three-dimensional measurement of each pipe, and the appropriate cutting surfaces are calculated by geometric analysis of the models with considering for ease of cutting work at the construction site. This paper described a modeling method of pipes, a calculation algorithm of the proper cutting surfaces of the spool, and a verification result of the calculation.

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