THE PROBLEM OF IDENTIFICATION OF HYDRAULIC RESISTANCE COEFFICIENTS IN MAKISTRAL GAS PIPELINE

2021 ◽  
pp. 6-11
Author(s):  
G. Gasymov
Keyword(s):  
Hydraulic Resistance ◽  
Group Identification ◽  
Numerical Approach ◽  
Transportation Systems ◽  
Gas Pipeline ◽  
Closed Loops ◽  
Hydraulic Network ◽  
Resistance Coefficients ◽  
Operating Regimes

A numerical approach, based on obtaining design formulas for the determination of hydraulic resistance coefficients of sites in pipeline transportation systems in the presence of the results of observations over a gas pipeline operating regimes, is proposed. The representation of the hydraulic network in the form of a directed graph allows to essentially reduce the number of equations in the system down to the number of closed loops. In the software implementation of the method described, for the solution of practical problems, group identification of the hydraulic resistance coefficients is provided for every eventuality.

scholarly journals Determination of Manganese in Welded Joint and Pipe Body of API X100 Grade SAWH and SAWL Pipe for Gas Pipeline Transportation Systems

2013 ◽  
Vol 25 (6) ◽  
pp. 3487-3490
Author(s):  
Xiaodong Shao ◽  
Xinli Han ◽  
Guangsan Song ◽  
Xiaodong He ◽  
Yangqin Liu ◽  
...  
Keyword(s):  
Welded Joint ◽  
Transportation Systems ◽  
Gas Pipeline ◽  
Pipeline Transportation

scholarly journals Investigation of hydraulic fitting losses

2018 ◽  
Vol 168 ◽  
pp. 02011 ◽  
Author(s):  
Marian Bojko ◽  
Milada Kozubková
Keyword(s):  
Flow Direction ◽  
Experimental Methods ◽  
Numerical Approach ◽  
Model Verification ◽  
Hydraulic Systems ◽  
Mathematical Methods ◽  
Standards And Regulations ◽  
Definition Of ◽  
Resistance Coefficients

Fluid flow in hydraulic systems, fittings, and piping causes hydraulic losses due to the change of flow direction and friction in the fluid. The main consequence of the resulting losses is the increase in the overall pressure gradient of the circuit. The paper is focused on the investigation of valve losses and the determination of resistance coefficients, the definition of which depends on the valve type. Methods of determination are of two types, i.e. experimental methods and mathematical methods. In the case of experimental methods, the procedures prescribed by the standards and regulations must be respected. Mathematical methods are related to defining an appropriate mathematical model and numerical approach. Both methods are applied to the ball valve and model verification is performed at the same time. The output of the thesis is the methodology for determination of resistance coefficients of valves with other diameters and other flowing media based on verified mathematical modeling.

Steady State Detection in Industrial Gas Turbines for Condition Monitoring and Diagnostics Applications

2014 ◽  
Author(s):  
Cesar Celis ◽  
Érica Xavier ◽  
Tairo Teixeira ◽  
Gustavo R. S. Pinto
Keyword(s):  
Steady State ◽  
Condition Monitoring ◽  
Gas Turbines ◽  
Signal Analysis ◽  
Operating Regime ◽  
State Detection ◽  
Industrial Gas Turbines ◽  
Monitoring And Diagnostics ◽  
Operating Regimes

This work describes the development and implementation of a signal analysis module which allows the reliable detection of operating regimes in industrial gas turbines. Its use is intended for steady state-based condition monitoring and diagnostics systems. This type of systems requires the determination of the operating regime of the equipment, in this particular case, of the industrial gas turbine. After a brief introduction the context in which the signal analysis module is developed is highlighted. Next the state of the art of the different methodologies used for steady state detection in equipment is summarized. A detailed description of the signal analysis module developed, including its different sub systems and the main hypotheses considered during its development, is shown to follow. Finally the main results obtained through the use of the module developed are presented and discussed. The results obtained emphasize the adequacy of this type of procedures for the determination of operating regimes in industrial gas turbines.

Détermination de la taille et du nombre d’échantillons devant être analysés en laboratoire pour la caractérisation statistique de la microstructure d’une roche argileuse

2020 ◽  
pp. 1
Author(s):  
Anne-Laure Fauchille ◽  
Bram van den Eijnden ◽  
Kevin Taylor ◽  
Peter David Lee
Keyword(s):  
Representative Volume Element ◽  
Numerical Approach ◽  
Volume Element ◽  
Méthode Statistique ◽  
Representative Volume ◽  
Microscopie Électronique ◽  
Random Composites ◽  
Sols Argileux ◽  
Microscopie Électronique À Balayage

À l’échelle du laboratoire, les roches argileuses sont des matériaux hétérogènes dont le comportement thermo-hydromécanique est en grande partie contrôlé par la microstructure. Le choix du nombre et de la taille des échantillons à étudier en laboratoire est déterminant pour appréhender la variabilité des propriétés de la roche argileuse à petite échelle. Cet article présente une méthode statistique permettant de préciser la surface (ou le volume) et le nombre d’échantillons à prendre en compte pour qu’une propriété p choisie caractérisant la microstructure, soit statistiquement représentative. Initialement établie dans un cas général par Kanit et al. (2003. Determination of the size of the representative volume element for random composites: statistical and numerical approach. Int J Solids Struct 40(13–14): 3647–3679), cette méthode consiste à partitionner un échantillon de propriété moyenne [see formula in PDF] connue, en sous-échantillons de surface D × D afin de calculer l’écart-type et l’erreur relative de la mesure de p en fonction de D. Cette méthode permet ainsi de définir des surfaces élémentaires représentatives de p en tenant compte de l’erreur relative par rapport à [see formula in PDF]. La méthode est d’abord présentée dans des cas généraux en 2D et 3D, et un exemple type est ensuite développé en 2D pour caractériser la fraction argileuse d’une lamine sédimentaire de Bowland (Royaume-Uni). La fraction surfacique argileuse est choisie comme propriété p, à partir d’une image grand-champ en microscopie électronique à balayage. La méthode est applicable en 2D et 3D sur les matériaux finement divisés autant sur les roches que sur les sols argileux, tant que l’échantillon considéré contient suffisamment d’éléments figurés (inclusions rigides ou pores dans une matrice par exemple) pour permettre l’utilisation des statistiques. L’apport principal visé pour la communauté des ingénieurs est dans la mesure du possible un meilleur ciblage de la quantité d’échantillons à prélever en forage pour mieux évaluer la variabilité des paramètres macroscopiques des roches argileuses. Les limites de la méthode sont ensuite discutées.

A least squares method for earthquake mechanism determination using S-wave data

1964 ◽  
Vol 54 (6A) ◽  
pp. 2037-2047
Author(s):  
Agustin Udias
Keyword(s):  
Least Squares ◽  
Statistical Evaluation ◽  
Least Squares Method ◽  
Numerical Approach ◽  
Focal Mechanisms ◽  
Least Square ◽  
S Wave ◽  
Double Couple ◽  
Earthquake Mechanism

abstract In this paper a numerical approach to the determination of focal mechanisms based on the observation of the polarization of the S wave at N stations is presented. Least-square methods are developed for the determination of the orientation of the single and double couple sources. The methods allow a statistical evaluation of the data and of the accuracy of the solutions.

Numerical Approach for Determination of Cutback Length to Estimate Dispersion and Loss Parameters of Terahertz Waveguides

2010 ◽  
Vol 49 (7) ◽  
pp. 072702
Author(s):  
Ken Ishikawa ◽  
Carlito Ponseca ◽  
Elmer S. Estacio ◽  
Satoru Takatori ◽  
Nobuhiko Sarukura ◽  
...  
Keyword(s):  
Numerical Approach ◽  
Terahertz Waveguides ◽  
Estimate Dispersion

A novel numerical approach for workspace determination of parallel mechanisms

2017 ◽  
Vol 31 (6) ◽  
pp. 3005-3015 ◽  
Author(s):  
Yiqun Zhou ◽  
Junchuan Niu ◽  
Zhihui Liu ◽  
Fuliang Zhang
Keyword(s):  
Numerical Approach ◽  
Parallel Mechanisms

scholarly journals Two Efficient Methods for Gas Distributive Network Calculation

2018 ◽  
Author(s):  
Dejan Brkić
Keyword(s):  
Pressure Drop ◽  
Thermodynamic Properties ◽  
Gas Flow ◽  
Flow Distribution ◽  
Gas Pipeline ◽  
Gas Flow Rate ◽  
Closed Loops ◽  
Loop Method ◽  
Hardy Cross ◽  
Flow Through

Today, two very efficient methods for calculation of flow distribution per branches of a looped gas pipeline are available. Most common is improved Hardy Cross method, while the second one is so-called unified node-loop method. For gas pipeline, gas flow rate through a pipe can be determined using Colebrook equation modified by AGA (American Gas Association) for calculation of friction factor accompanied with Darcy-Weisbach equation for pressure drop and second approach is using Renouard equation adopted for gas pipeline calculation. For the development of Renouard equation for gas pipelines some additional thermodynamic properties are involved in comparisons with Colebrook and Darcy-Weisbach model. These differences will be explained. Both equations, the Colebrook’s (accompanied with Darcy-Weisbach scheme) and Renouard’s will be used for calculation of flow through the pipes of one gas pipeline with eight closed loops which are formed by pipes. Consequently four different cases will be examined because the network is calculated using improved Hardy Cross method and unified node-loop method. Some remarks on optimization in this area of engineering also will be mentioned.

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