scholarly journals Refinement of the calculation model of vibrations for cylindrical supports of structures of oil and gas platforms during relocation

2021 ◽  
pp. 12-17
Author(s):  
О.Е. Сысоев ◽  
Е.О. Сысоев ◽  
А.Ю. Добрышкин
Keyword(s):  
Mathematical Model ◽  
Oil And Gas ◽  
Experimental Studies ◽  
Added Mass ◽  
Calculation Model ◽  
Offshore Platforms ◽  
Cylindrical Structures ◽  
External Forces ◽  
The Mathematical Model ◽  
Experimental And Theoretical Studies

В статье рассмотрена проблема предотвращения разрушения опор нефтегазовых морских платформ при передислокации. Цилиндрические конструкции опор нефтегазовых платформ очень чувствительны к динамическим воздействиям внешних сил, которые вызывают колебания конструкций и явление резонанса, особенно при передислокации. Цилиндрические опоры платформ также несут дополнительные массы (оборудование, антиледовый пояс и т.п.), которые оказывают значительное влияние на динамику работы оболочек. В статье уточнена математическая модель колебаний оболочек, несущих дополнительную массу, на основе теории Рейснера. Проведены экспериментальные исследования на уменьшенных моделях оболочек, проверки уточнённой математической модели, показано сравнение экспериментальных и теоретических исследований. Основное отличие скорректированной математической модели заключается в присутствии нового параметра, учитывающего влияния наличия малой дополнительной массы. Уточненнаяматематическая модель позволит более точно рассчитывать частоты колебаний конструкции в режиме online, и предотвращать возможные разрушения цилиндрических опор конструкций нефтегазовых платформ при передислокации. The article deals with the problem of preventing the destruction of the supports of oil and gas offshore platforms during relocation. Cylindrical structures of oil and gas platform supports are very sensitive to dynamic influences of external forces, which cause vibrations of structures and the phenomenon of resonance, especially during relocation. Cylindrical platform supports also carry attached masses (equipment, anti-ice belt, etc.), which have a significant impact on the dynamics of the shells operation. The article refines the mathematical model of vibrations of shells carrying the added mass on the basis of Reisner's theory. Experimental studies are carried out on reduced models of shells, verification of the refined mathematical model, a comparison of experimental and theoretical studies is shown. The main difference of the corrected mathematical model is the presence of a new parameter that takes into account the influence of the presence of a small added mass. The refined mathematical model will make it possible to more accurately calculate the vibration frequencies of the structure online, and prevent possible destruction of the cylindrical supports of the structures of oil and gas platforms during relocation.

scholarly journals DIESEL SUPPLY PLANNING FOR OFFSHORE PLATFORMS BY A MATHEMATICAL MODEL BASED ON THE VEHICLE ROUTING PROBLEM WITH REPLENISHMENT

2016 ◽  
Author(s):  
Rodrigo De Alvarenga Rosa ◽  
Henrique Fiorot Astoures ◽  
André Silva Rosa
Keyword(s):  
Mathematical Model ◽  
Vehicle Routing ◽  
Vehicle Routing Problem ◽  
Oil And Gas ◽  
Offshore Platforms ◽  
Oil Exploration ◽  
Routing Problem ◽  
Model Based ◽  
Supply Planning ◽  
The Mathematical Model

Oil exploration in Brazil is mainly held by offshore platforms which require the supply of several products, including diesel to maintain its engines. One strategy to supply diesel to the platforms is to keep a vessel filled with diesel nearby the exploration basin. An empty boat leaves the port and goes directly to this vessel, then it is loaded with diesel. After that, it makes a trip to supply the platforms and when the boat is empty, it returns to the vessel to be reloaded with more diesel going to another trip. Based on this description, this paper proposes a mathematical model based on the Vehicle Routing Problem with Intermediate Replenishment Facilities (VRPIRF) to solve the problem. The purpose of the model is to plan the routes for the boats to meet the diesel requests of the platform. Given the fact that in the literature, papers about the VRPIRF are scarce and papers about the VRPIRF applied to offshore platforms were not found in the published papers, this paper is important to contribute with the evolution of this class of problem, bringing also a solution for a real application that is very important for the oil and gas business. The mathematical model was tested using the CPLEX 12.6. In order to assess the mathematical model, tests were done with data from the major Brazilian oil and gas company and several strategies were tested.DOI: http://dx.doi.org/10.4995/CIT2016.2016.2217

EXPERIMENTAL STUDIES OF CAR PROPERTIES ON A PHYSICAL MODEL

2019 ◽  
pp. 10-16
Author(s):  
Oleksii Timkov ◽  
Dmytro Yashchenko ◽  
Volodymyr Bosenko
Keyword(s):  
Mathematical Model ◽  
Remote Control ◽  
Physical Model ◽  
Model Experiment ◽  
Experimental Studies ◽  
Electrical Energy ◽  
Short Term ◽  
Motor Current ◽  
Memory Card ◽  
The Mathematical Model

The article deals with the development of a physical model of a car equipped with measuring, recording and remote control equipment for experimental study of car properties. A detailed description of the design of the physical model and of the electronic modules used is given, links to application libraries and the code of the first part of the program for remote control of the model are given. Atmega microcontroller on the Arduino Uno platform was used to manage the model and register the parameters. When moving the car on the memory card saved such parameters as speed, voltage on the motor, current on the motor, the angle of the steered wheel, acceleration along three coordinate axes are recorded. Use of more powerful microcontrollers will allow to expand the list of the registered parameters of movement of the car. It is possible to measure the forces acting on the elements of the car and other parameters. In the future, it is planned to develop a mathematical model of motion of the car and check its adequacy in conducting experimental studies on maneuverability on the physical model. In addition, it is possible to conduct studies of stability and consumption of electrical energy. The physical model allows to quickly change geometric dimensions and mass parameters. In the study of highway trains, this approach will allow to investigate the various layout schemes of highway trains in the short term. It is possible to make two-axle road trains and saddle towed trains, three-way hitched trains of different layout. The results obtained will allow us to improve not only the mathematical model, but also the experimental physical model, and move on to further study the properties of hybrid road trains with an active trailer link. This approach allows to reduce material and time costs when researching the properties of cars and road trains. Keywords: car, physical model, experiment, road trains, sensor, remote control, maneuverability, stability.

scholarly journals Use of the mathematical model of the ignition system to analyze the spark discharge, including the destruction of spark plug electrodes

Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Sebastian Różowicz
Keyword(s):  
Mathematical Model ◽  
Experimental Studies ◽  
Fuel Mixture ◽  
Spark Discharge ◽  
Fuel Additives ◽  
Ignition System ◽  
Spark Plug ◽  
The Mathematical Model

Abstract The paper presents the results of analytical and experimental studies concerning the influence of different kinds of fuel additives on the quality of the spark discharge for different configurations of the ignition system. The wear of the spark plug electrode and the value of spark discharge were determined for various impurities and configurations of the air-fuel mixture.

Аpplication of the mathematical model of human torso for modeling abbreval influence in wound ballistics

2020 ◽  
Vol 22 (3) ◽  
pp. 132-139
Author(s):  
A. V. Denisov ◽  
M. D. Stepanov ◽  
N. A. Haraldin ◽  
A. V. Stepanov ◽  
A. I. Borovkov ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Element Model ◽  
Mechanical Action ◽  
Calculation Model ◽  
Calculation Results ◽  
Automated Processing ◽  
Original Calculation ◽  
Using Data ◽  
The Mathematical Model ◽  
Selection Of

Abstract. In the work, a review of scientific articles on the behavior of tissues and organs of the human body under local mechanical effects on it, as well as a description of the physico-mechanical properties of biological materials. The selection of mechanical behavior for each biological material as part of a mathematical model of the human torso was carried out, its finite element model was created, validation experiments were modeled using data presented in the literature. An original calculation model of a human torso with a tuned interaction of organs with each other was developed. Contact interaction parameters are determined. The developed computational model of a human torso was verified based on data from open sources for an experiment with mechanical action by a cylindrical impactor. An algorithm for processing pressure and acceleration graphs has been implemented in order to obtain tolerance curves. A specialized modular program has been created for the automated processing of calculation results and the output of the main results. 42 numerical tests were carried out simulating the entry of a steel ball into each of 21 zones for power engineers of 40 and 80 J. According to the results of the tests for each organ, pressure and acceleration tolerance curves were obtained, animations of the behavior of organs under shock were created, visualization of the pressure field propagation in organs was obtained torso.

A Mathematical Calculation Method for Hysteresis Characteristics Analysis of Arc-Shaped Finger Seal

2020 ◽  
Author(s):  
Chun-Hua Du ◽  
Yan-Chao Zhang ◽  
Ya-Hui Cui ◽  
Shu-Na Dong ◽  
Hong-Hu Ji ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Structural Parameters ◽  
Maximum Error ◽  
Calculation Model ◽  
Correction Coefficient ◽  
Research Results ◽  
Characteristics Analysis ◽  
Leakage Characteristics ◽  
The Mathematical Model ◽  
Hysteresis Characteristics

Abstract In order to accurately predict the hysteresis characteristics of finger seal, the minimum hysteresis which can directly reflect the hysteresis of finger seal is proposed to characterize the hysteresis of finger seal. The mathematical model for calculating the minimum hysteresis of finger seal is established, the correction coefficient in the mathematical model is determined, and the mathematical model is verified by experiments. The influence of the structure and working condition parameters of finger laminates on the hysteresis characteristics is studied based on the modified calculation model, and the rule of influence is obtained in the end. Research results show that the maximum error between the leakage characteristics numerical calculation of finger seal base on modified calculation model and the experiment results is 7.64%, and the mathematical model of the minimum hysteresis is reasonable and reliable. The descending order of influence degree of structural parameters on the hysteresis characteristics of finger seal is: thickness of each finger laminate, finger repeat angle, arc radius of the finger beam arcs‘ centers, diameter of the finger base circle, width of the interstice between fingers, arc radius of finger beam. The research results provide a theoretical basis for further research on the influence of hysteresis on the finger seal leakage characteristics and the optimal design of finger seal structure.

Mobile Worm-Like Robots for Pipe Inspection

2015 ◽  
pp. 168-218 ◽  
Author(s):  
Sergey Fedorovich Jatsun ◽  
Andrei Vasilevich Malchikov
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
Mobile Robots ◽  
Experimental Studies ◽  
Design Parameters ◽  
Robot Motion ◽  
Robot Dynamics ◽  
Confined Space ◽  
Pipe Inspection ◽  
The Mathematical Model

This chapter describes various designs of multilink mobile robots intended to move inside the confined space of pipelines. The mathematical model that describes robot dynamics and controlled motion, which allows simulating different regimes of robot motion and determining design parameters of the device and its control system, is presented. The chapter contains the results of numerical simulations for different types of worm-like mobile robots. The experimental studies of the in-pipe robots prototypes and their analyses are presented in this chapter.

scholarly journals Belt conveyor failure simulation at the design stage with transverse displacements of the belt

2020 ◽  
Vol 168 ◽  
pp. 00056
Author(s):  
Vitalii Monastyrskyi ◽  
Serhii Monastyrskyi ◽  
Denis Nomerovskyi ◽  
Borys Mostovyi
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Fourier Transform ◽  
Adaptive Control ◽  
Design Stage ◽  
Belt Conveyor ◽  
Failure Simulation ◽  
The Fourier Transform ◽  
External Forces ◽  
The Mathematical Model

To find possible conveyor failures at the design stage means to determine a transverse belt displacement and compare the obtained data with the permissible ones. The dynamic problem of the belt movement on the conveyor has been defined. Resistance and external forces, limits of the belt displacement have been determined. The transverse belt displacement can be described by partial differential equations. To solve the problem, the Fourier transform has been used. Change patterns in the transverse belt conveyor displacement dependent on conveyor’s parameters, type of load, and skewing of the idlers along the conveyor have been obtained. The results agree with experimental data. The method of adaptive control of the transverse belt displacement has been described. The essence of this method is to adapt the model of the moving belt in the conveying trough to changed conditions and to reveal the uncertainty of the control with the known parameters of the mathematical model.

Theoretical and Experimental Study of the Dynamics of the Tripod-Ball Sliding Joint With Clearance

2001 ◽  
Author(s):  
Jia Xiaohong ◽  
Ji Linhong ◽  
Jin Dewen ◽  
Zhang Jichuan
Keyword(s):  
Mathematical Model ◽  
Equations Of Motion ◽  
Experimental Studies ◽  
Active System ◽  
New Concepts ◽  
Sliding Joint ◽  
New Type ◽  
Set Up ◽  
The Mathematical Model ◽  
Kane Method

Abstract Clearance is inevitable in the kinematic joints of mechanisms. In this paper the dynamic behavior of a crank-slider mechanism with clearance in its tripod-ball sliding joint is investigated theoretically and experimentally. The mathematical model of this new-type joint is established, and the new concepts of basal system and active system are put forward. Based on the mode-change criterion established in this paper, the consistent equations of motion in full-scale are derived by using Kane method. The experimental rig was set up to measure the effects of the clearance on the dynamic response. Corresponding experimental studies verify the theoretical results satisfactorily. In addition, due to the nonlinear elements in the improved mathematical model of the joint with clearance, the chaotic responses are found in numerical simulation.

Adsorption-Desorption Processes in Adsorption Chillers

2016 ◽  
Vol 20 (2) ◽  
pp. 81-89
Author(s):  
Monika Gwadera
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Mass Transfer ◽  
Experimental Studies ◽  
Operating Principle ◽  
Adsorption Desorption ◽  
The Mathematical Model

AbstractThe aim of this paper is to present the adsorption chillers technology. The operating principle of these systems, the adsorbent-adsorbate pairs that are frequently applied and the enhancement techniques that allow improvement of their efficiency are presented. Analysis of the mass transfer and principles of mathematical modeling of such systems are also discussed. In the further part of the text, the results of experimental studies and comparison of these results with calculations based on the mathematical model of adsorption were presented.

scholarly journals DEVELOPMENT AND RESEARCH OF PROMISING SCHEMES FOR DIVIDING PIPES INTO DIMENSIONAL BILLETS

2021 ◽  
pp. 30-37
Author(s):  
Sergii Karnaukh
Keyword(s):  
Mathematical Model ◽  
Experimental Studies ◽  
Connecting Rod ◽  
High Quality ◽  
Cutting Knife ◽  
3D Software ◽  
The Mathematical Model ◽  
Cut Surface ◽  
Deform 3D

The purpose of this work is to study the known method of division of pipes by introducing a figure knife and the development of promising designs of equipment for division of pipes into measured workpieces. Based on the analysis of the actuating crank-slider mechanisms used in the equipment for division of pipes into measured workpieces, promising schemes of short-connecting rod mechanisms have been discovered that provide a local pipe section along the perimeter. The developed design of the device for dividing pipes into dimensional workpieces by the eccentric twisting method, which contains a wedge-joint mechanism in combination with a compact circular actuator, also allows to reduce energy and power costs for separation, reduce the consequences of instantaneous unloading of equipment and ensure high quality workpieces. A mathematical model of the proposed equipment was developed and the modeling of the cutting process was carried out using the DEFORM-3D software package. The analysis of the results obtained showed that in the extreme positions of the knives, jamming of the knives is possible. To eliminate jamming, it is necessary that the knives do not reach the extreme position. The adequacy of the mathematical model is confirmed by experimental studies. The error of the calculated and measured values of the torque on the cutting knife does not exceed 10%. This is due to the need for a more correct accounting of friction on the contact surfaces of the equipment. Cut tubular blanks have high geometric accuracy and high quality of the cut surface.

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