scholarly journals REASONS FOR THE CHOICE OF THE THERMAL PIPE FOR THE COMPLEX COOLING SYSTEM OF THE COMBINED CUTTING TOOLS

2017 ◽  
Vol 2017 (1) ◽  
pp. 6-11
Author(s):  
Юрий Дубров ◽  
Yuriy Dubrov ◽  
Александр Чукарин ◽  
Дмитрий Дубров ◽  
Dmitriy Dubrov ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Phase Transitions ◽  
Heat Exchange ◽  
Cooling System ◽  
Cutting Tools ◽  
Cutting Process ◽  
Dry Cutting ◽  
Aggregate State ◽  
Duration Time ◽  
The Mathematical Model

The mathematical model of heat exchange in a cooling system of the combined cutting tools in case of dry cutting is provided. Absorption of heat is reached in case of change of aggregate state of fusible substances and is based on application of phase transitions of the first sort. As a result of the solution of a task of Stefan cutting process thermostabilization duration time is determined.

An Optimization of Automated Process Planning for Manufacturing Prismatic Parts on a Machining Center

2015 ◽  
Vol 789-790 ◽  
pp. 1270-1274
Author(s):  
Janjira Kongchuenjai ◽  
Suksan Prombanpong
Keyword(s):  
Mathematical Model ◽  
Process Planning ◽  
Cutting Tools ◽  
Cnc Machining ◽  
Total Production ◽  
Machining Time ◽  
Optimal Sequence ◽  
Machining Center ◽  
Prismatic Parts ◽  
The Mathematical Model

One of the objectives of process planning optimization is to diminish machining time. Nowadays a lot of research papers presented different algorithms to solve this classic problem. Thus, the optimal sequence of parts in the machining operations by considering fixture faces, part faces, number of operations and number of tools is presented in this paper. The mathematical model based on the integer linear programming is developed to minimize the total production time of the prismatic parts manufactured on a CNC machining center equipped with the tombstone-type fixture. The time required for machining, tool traveling and tool changing is taken into consideration under relevant constraints such as precedence, fixture and available cutting tools. The optimal process plan can be obtained from the mathematical model and it is considered practical and acceptable.

Optimal Design of Dynamic Secondary Cooling of Continuous Casting

2012 ◽  
Vol 472-475 ◽  
pp. 1907-1910
Author(s):  
Yi Wang ◽  
Xin Jian Ma
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Finite Element ◽  
Continuous Casting ◽  
Cooling System ◽  
Solidification Process ◽  
Element Model ◽  
Secondary Cooling ◽  
The Mathematical Model ◽  
The Finite Element Model

Numerical simulation of the secondary cooling is applied to the design of continuous casting. The mathematical model for solidification process of the strand under air-mist was established and calculated with the finite element model. The model is used to calculate the feasible operating range of the continuous casting machines. The dynamic secondary cooling system has been analyzed with consideration of the thermo mechanical principles and numerical model. The adequacy of the model has been confirmed with experimental results.

Mathematical model of cutting process of cutting tools with a side-mounted multifaceted, requiring no sharpening plates

2018 ◽  
Vol 92 (4) ◽  
pp. 132-138
Author(s):  
V.A. Nastasenko ◽  
◽  
M.V. Babiy ◽  
V.O. Protsenko ◽  
◽  
...  
Keyword(s):  
Mathematical Model ◽  
Cutting Tools ◽  
Cutting Process

Probabilistic model of structural phase transition in perovskites

2021 ◽  
pp. 2150211
Author(s):  
S. H. Jabarov ◽  
R. T. Aliyev ◽  
N. A. Ismayilova
Keyword(s):  
Mathematical Model ◽  
Phase Transitions ◽  
Crystal Structures ◽  
Structural Phase ◽  
Random Variable ◽  
Structural Phase Transitions ◽  
The Moment ◽  
The Mathematical Model ◽  
First Time

In this work, the crystal structures and phase transitions of compounds with perovskite structure were investigated. The classification of structural phase transitions in perovskites was carried out, the most common crystal structures and structural phase transitions were shown. A mathematical model was constructed, a theorem was given and proved for the probability of a possible transition. The formulas [Formula: see text] and [Formula: see text] are given for the mathematical expectation and variance of random variable [Formula: see text], which is the moment when the stochastic process [Formula: see text] deviation from the boundary [0, [Formula: see text]] interval for the first time. According to the mathematical model, one of the trajectories of random processes corresponding to the phase transitions that occur in perovskites is constructed.

scholarly journals Investigation of Thermodynamic Properties of the Slurry of the Molding Process Beryllium Ceramics

Proceedings ◽  
2018 ◽  
Vol 2 (22) ◽  
pp. 1391
Author(s):  
Zamira Sattinova ◽  
Gaukhar Ramazanova ◽  
Bakhytzan Assilbekov ◽  
Elmira Mussenova
Keyword(s):  
Thermal Conductivity ◽  
Mathematical Model ◽  
Thermal Properties ◽  
Heat Exchange ◽  
Thermodynamic Properties ◽  
Physical Properties ◽  
Beryllium Oxide ◽  
Molding Process ◽  
The Mathematical Model

Obtaining of ceramic fabrications by hot molding from dispersion materials with anomalous physical properties, such as BeO is particularly complicated. In this case, the difficulties of obtaining of quality products were caused firstly by thermal properties of beryllium oxide, in particular, its unique thermal conductivity. Results of experiments and calculations of the mathematical model of the motion and heat exchange of the slurry mass in the annular cavity are presented. The results of experiments and calculations show the process of molding of the slurry in the annular cavity.

Study on the Adhering Disrepair and Groove Optimization of Cutting Tools for Difficult-to-Machine Materials

2006 ◽  
Vol 315-316 ◽  
pp. 715-719 ◽  
Author(s):  
Zhen Jia Li ◽  
Yao Nan Cheng ◽  
Guang Yu Tan ◽  
Yan Bo Wang ◽  
Yi Ming Rong
Keyword(s):  
Mathematical Model ◽  
Cutting Tools ◽  
Rake Face ◽  
Machine Material ◽  
Milling Temperature ◽  
The Mathematical Model

In the course of the milling experiments with the difficult-to-machine material 3Cr-1Mo-1/4V steel, we have found the substance of the adhering disrepair. In addition, we forecast the predominant capability of the waved-edge milling insert with complex 3-D grooves by the synthetically blurry judgement. Eventually, we give the mathematical model between the milling temperature and the maximal adhering disrepair depth of the rake face, and analyze the rule that the milling temperature affects the adhering disrepair. What’s more, we testify the predominant capability of the waved-edge milling insert.

A feedback temperature control in a chemical reactor with high inertia of its cooling system

1984 ◽  
Vol 49 (7) ◽  
pp. 1642-1652 ◽  
Author(s):  
Josef Horák ◽  
František Jiráček ◽  
Libuše Ježová
Keyword(s):  
Mathematical Model ◽  
Temperature Control ◽  
Cooling System ◽  
Batch Reactor ◽  
Time Derivative ◽  
Exothermic Reaction ◽  
Chemical Reactor ◽  
The One ◽  
The Mathematical Model ◽  
The Given

In this work we compare simple algorithms for the one-off feedback temperature control of the reaction mixture in a batch reactor during an exothermic reaction. The aim of the control was to maintain the temperature of the mixture within the given range, and simultaneously, to minimize the number of the regulator switchings. The temperature control of the mixture was being performed at conditions when working states of the reactor in an open regulation loop are unstable and when the response of the cooler to regulation is slow. The following control algorithms were compared: P - regulator, PD - regulator and algorithms based on a prediction mathematical model including its adaptive variant. The results indicate that the algorithms based on the mathematical model are more efficient. However, the precision of the control can be diminished due to error in the time derivative of the temperature of the reaction mixture which forms the input to the prediction model. The adaptive variant of the algorithms was advantageous in cases when it was necessary to make up for significant errors in initial estimates of parameters of the prediction mathematical model.

A General Mathematical Model for Gears Cut by CNC Hobbing Machines

1997 ◽  
Vol 119 (1) ◽  
pp. 108-113 ◽  
Author(s):  
Shinn-Liang Chang ◽  
Chung-Biau Tsay ◽  
Shigeyoshi Nagata
Keyword(s):  
Mathematical Model ◽  
Degree Of Freedom ◽  
Cutting Process ◽  
Generation Process ◽  
Cutting Mechanism ◽  
Gear Cutting ◽  
Different Types ◽  
General Mathematical Model ◽  
Crossed Axes ◽  
The Mathematical Model

A hobbing machine’s cutting mechanism is a mechanism with multi-degree of freedom during the cutting process. In this paper, we propose a general gear mathematical model simulating the generation process of a 6-axis CNC hobbing machine based on the cutting mechanism of CNC hobbing machine and worm-type hob cutter. The proposed gear mathematical model can be applied to simulate different types of gear cutting. Some examples are included to verify the mathematical model. Also, a novel type of gear named “Helipoid” which can be used in crossed axes transmission is proposed. The proposed general gear mathematical model can facilitate a more thorough understanding of generation processes and toward the development of novel types of gears.

scholarly journals Conjugated Heat Exchange in Heat Treatment of Aluminum Ingots Simulation

2021 ◽  
Vol 2096 (1) ◽  
pp. 012053
Author(s):  
A S Gorshenin ◽  
J I Rakhimova ◽  
N P Krasnova
Keyword(s):  
Heat Transfer ◽  
Heat Treatment ◽  
Mathematical Model ◽  
Heat Exchange ◽  
Conjugate Heat Transfer ◽  
Physical And Mechanical Properties ◽  
Aluminum Ingot ◽  
Casting Aluminum ◽  
Cooling Air ◽  
The Mathematical Model

Abstract Casting aluminum to obtain semi-finished products - round ingots, due to uneven cooling in the mold, leads to various defects that affect further machining. To eliminate such defects, heat treatment is carried out - homogenization annealing. One of the homogenization important stages is the cooling of the ingots after heating at a rate that does not lead to the ingot quenching. The cooling medium is air. Knowing the conditions of heat exchange between the cooling air and the high-temperature aluminum billet makes it possible to obtain the ingot’s necessary physical and mechanical properties. The article describes the developed mathematical model of conjugate heat transfer during homogenization annealing of aluminum ingot. It allows analytically calculating the temperature of the ingots depending on the cooling time. To verify the data obtained by the mathematical model, the conjugate heat transfer in the ANSYS program was simulated.

scholarly journals Thermodynamic analysis of expansion process of screw expander in wet steam area

2021 ◽  
Vol 5 (4) ◽  
pp. 39-47
Author(s):  
A. M. Kalashnikov ◽  
◽  
G. I. Chernov ◽  
V. L. Yusha ◽  
◽  
...  
Keyword(s):  
Mathematical Model ◽  
Heat Exchange ◽  
Thermodynamic Analysis ◽  
Scientific Work ◽  
Main Rotor ◽  
Wet Steam ◽  
Expansion Process ◽  
The Mathematical Model ◽  
Thermodynamic Equations ◽  
Angle Of Rotation

In this scientific work, the process of expansion of wet steam with different values of the inlet degree of dryness in a screw expander is considered. The study is carried out on the basis of the developed mathematical model, which includes both the basic thermodynamic equations and the process of heat exchange of the working substance with the environment in the process of expansion. During the study of the expansion process in the area of wet steam in a screw expander, a mathematical model of this process is developed. The mathematical model is verified by comparing the results obtained on its basis with the results obtained by other researchers on an identical object. It can be seen from the results obtained that at values of the initial degree of dryness greater than 0,01, the distributions of pressures and temperatures practically do not depend on its value. When the initial dryness values are less than 0,01, it begins to have a significant effect on the distribution of pressure and temperature over the angle of rotation of the main rotor of the screw expander.

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