Modeling of conditions for formation of melted metal bath and weld during facing with consumable electrode and additional fi ller wire

2020 ◽  
pp. 247-255
Author(s):  
S.S. Poloskov ◽  
V.A. Erofeev ◽  
M.A. Sholokhov
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Mathematical Model ◽  
Computer Simulation ◽  
Boundary Conditions ◽  
Consumable Electrode ◽  
Metal Bath ◽  
Transverse Vibrations ◽  
Pressure Equilibrium ◽  
Melted Metal

The capabilities of computer simulation of complex multifactorial surfacing processes are discussed. Physical and mathematical model for the formation of melted metal bath and weld during consumable electrode surfacing with additional fi ller wire of parts and components of pipeline valves is presented. The basis of the model is equations system of heat transfer and pressure equilibrium on the surface of the melt. In the boundary conditions of the equations, change in the geometry of the surface due to transverse vibrations of the surfacing torch is taken into consideration. Numerical solution of the equations system showed that the main source of heat is heat from the droplets of the electrode and fi ller materials, its distribution is mainly determined by the amplitude and period of transverse vibrations. The results of process numerical simulation are presented. The results of the study are used in the development of innovative technological processes for surfacing of parts and components of pipeline valves.

scholarly journals The Non-Stationary Thermal Mode for Barrier Building Constructions in Non-Symmetric Boundary Conditions

2018 ◽  
Vol 7 (3.2) ◽  
pp. 535
Author(s):  
Olena Borshch ◽  
Volodymyr Borshch ◽  
Dmytro Guzyk
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Mathematical Model ◽  
Boundary Conditions ◽  
Thermal Diffusion ◽  
Thermal State ◽  
Thermal Mode ◽  
Temperature Mode ◽  
Deep Layers

In barrier building constructions the heat transfer occurs both at the expense of thermal conductivity and as a result of liquid and air vapors resistance. The mechanism of such resistance differs from classical processes of diffusion and the laws of hydrodynamics for integral medium.The temperature mode of the surface and deep layers of barrier building constructions in non-symmetric boundary conditions was     analyzed. A mathematical model was developed that characterizes the change in the thermal state of barrier constructions during thermal diffusion. The method for calculating the non-stationary thermal modes of flat walls was presented.  

Evaluation of boundary conditions for a mathematical model of heat transfer in a glass furnace

1996 ◽  
Vol 53 (3) ◽  
pp. 69-71 ◽  
Author(s):  
V. G. Lisienko ◽  
V. B. Kut'in ◽  
S. N. Gushchin ◽  
B. A. Fetisov
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Boundary Conditions ◽  
Glass Furnace

scholarly journals Mathematical model of heat transfer in roll caliber

2019 ◽  
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Boundary Value Problem ◽  
Boundary Conditions ◽  
Heat Equation ◽  
Rolling Mill ◽  
Thermal Process ◽  
Stationary Heat

A physical model of the thermal process in the roll caliber during the rolling of the tape on a two-roll rolling mill was constructed. A mathematical model of the temperature field of a rolling hollow roll of a rolling state of a cylindrical shape rotating about its axis with constant angular velocity is proposed. The mathematical model takes into account different conditions of heat exchange of the inner and outer surfaces of the roll with the belt and its surrounding environment. The temperature field of a hollow roll of a rolling mill is considered as an initial boundary-value problem for a homogeneous non-stationary heat equation with inhomogeneous, nonlinear boundary conditions, which also depend on the angle of rotation of the roll around its axis. The equation describes the temperature field of the rolls during uncontrolled heat transfer during rolling. It significantly depends on the time and number of revolutions around its axis. With a large number of revolutions of the roll around its axis, a quasi-stationary temperature distribution occurs. Therefore, the simplified problem of determining a quasistationary temperature field, which is associated with a thermal process that is time-independent, is considered further in the work. In this case, the temperature field is described using the boundary value problem in a ring for a homogeneous stationary heat equation with inhomogeneous boundary conditions and heat transfer conditions outside the ring, which lie from the angular coordinate. After the averaging operation, the solution of this problem is reduced to solving the equivalent integral equation of Hammerstein type with a kernel in the form of the Green's function. The Mathcad computer mathematical system builds the temperature distribution of the roll surface. An algorithm for solving a inhomogeneous problem was developed and the temperature distribution of the roll was constructed.

THERMAL RESISTANCE OF POWER SEMICONDUCTOR MODULES OF SOLDERED CONSTRUCTION

2020 ◽  
Vol 5 ◽  
pp. 122-130
Author(s):  
S.I. MATYUKHIN ◽  
D.O. MALYI ◽  
A.S. VISHNYAKOV ◽  
E.Yu. ORLOV ◽  
V.I. KAZAKOV
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Computer Simulation ◽  
Thermal Resistance ◽  
Comsol Multiphysics ◽  
Power Semiconductor ◽  
Transfer Processes ◽  
Main Effect

The heat transfer processes in power semiconductor modules of soldered construction are studied using the methods of computer simulation in Comsol Multiphysics software. The problem of the thermal resistance of such modules is solved. The factors showing the main effect on the thermal resistance of the modules are studied. A mathematical model allowing engineering calculations of this resistance is developed.

Natural Convection of Nanofluid in a Triangle Cavity with Different Angular Positions

2020 ◽  
Vol 12 (3) ◽  
pp. 325-329
Author(s):  
Mohsen Rostami ◽  
Mohammad Saleh Abadi
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Natural Convection ◽  
Flow Field ◽  
Boundary Conditions ◽  
Angular Position ◽  
Numerical Results ◽  
Heat Transfer Characteristics ◽  
Current Structure ◽  
Flow And Heat Transfer

The effects of the angular position on the flow and heat transfer of the nanofluid in a triangular cavity is investigated numerically. A triangular cavity is chosen with the same boundary conditions as the published results are available. The comparison between the current numerical results with the available data is made to show the accuracy of the numerical simulation. The current structure of triangular cavity is rotated to investigate the effects of various angular positions on the flow and heat transfer characteristics of nanofluid. For this purpose, the equations of continuity, momentum and energy are solved numerically. The results show that the hot fluid is more freely penetrated into the domain by increasing of the angular position. The velocity of fluid in the flow field becomes maximum for the angle of 120 . Also, the creation of vortices in the flow field depends on the value of angular position.

Blood flow of MHD non-Newtonian nanofluid with heat transfer and slip effects

2020 ◽  
Vol 30 (11) ◽  
pp. 4883-4908 ◽  
Author(s):  
Asmaa F. Elelamy ◽  
Nasser S. Elgazery ◽  
R. Ellahi
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Numerical Simulation ◽  
Mathematical Model ◽  
Blood Flow ◽  
Heart Valve ◽  
Vascular Resistance ◽  
Bacterial Growth ◽  
Valve Prosthesis ◽  
Content Type

Purpose This paper aims to investigate a mathematical model with numerical simulation for bacterial growth in the heart valve. Design/methodology/approach For antibacterial activities and antibodies properties, nanoparticles have been used. As antibiotics are commonly thought to be homogeneously dispersed through the blood, therefore, non-Newtonian fluid of Casson micropolar blood flow in the heart valve for two dimensional with variable properties is used. The heat transfer with induced magnetic field translational attraction under the influence of slip is considered for the resemblance of the heart valve prosthesis. The numeral results have been obtained by using the Chebyshev pseudospectral method. Findings It is proven that vascular resistance decreases for increasing blood velocity. It is noted that when the magnetic field will be induced from the heart valve prosthesis then it may cause a decrease in vascular resistance. The unbounded molecules and antibiotic concentration that are able to penetrate the bacteria are increased by increasing values of vascular resistance. The bacterial growth density cultivates for upswing values of magnetic permeability and magnetic parameters. Originality/value To the best of the authors’ knowledge, this is the first study to investigate a mathematical model with numerical simulation for bacterial growth in the heart valve.

scholarly journals Numerical simulation of temperature field in the vertical Bridgman method crystal growth

10.30544/130 ◽  
2015 ◽  
Vol 21 (1) ◽  
pp. 25-34
Author(s):  
Srdjan Perišić ◽  
Ahmed Ali Awhida ◽  
Vesna Radojević ◽  
Dejan Davidović ◽  
Dejan Trifunović ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Mathematical Model ◽  
Crystal Growth ◽  
Numerical Data ◽  
Sufficient Accuracy ◽  
The Finite Element Method ◽  
Growth Regime ◽  
Vertical Bridgman ◽  
The Mathematical Model

The mathematical model for heat transfer during the Bridgeman crystal growth, using the finite element method and the obtained result аre presented. Some modifications to the method were introduced in order to incorporate the data obtained experimentally. Solving the model enabled comparison of the experimental and numerical data and to obtain sufficient accuracy. The model was used to calculate the temperature gradient in the sample and the calculated gradient was in accordance with the observed crystal growth regime.

Modeling of work of plate water evaporation coolers of indirect operation principle

10.12737/2199 ◽  
2014 ◽  
Vol 3 (4) ◽  
pp. 160-166
Author(s):  
Шацкий ◽  
Vladimir Shatskiy ◽  
Гулевский ◽  
Vyacheslav Gulevskiy
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Boundary Conditions ◽  
Cross Section ◽  
Parabolic Type ◽  
Water Evaporation ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Proposed Model ◽  
Complex Mathematical Model

More complex mathematical model is proposed which is a system of partial differential equations of elliptic and parabolic type with the corresponding initial and boundary conditions, which are not involved in the heat transfer coefficients, the deter-mination of the numerical values of which is very difficult. For its implementation diffe-rence analogue of the proposed model was built with Nx steps along the length of the channel, Ny steps along the section of channels, Ny / 2 +1 steps of the cross section of the plate. The presented model and the method of its implementation makes it possible to determine the temperature of the air flows along the length of coolers that offers a choice of the geometric parameters.

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