Mathematical model and numerical analysis of heat-transfer processes associated with the melting of polymers in plasticating extruders

1985 ◽  
Vol 48 (1) ◽  
pp. 60-64 ◽  
Author(s):  
V. P. Pervadchuk ◽  
N. M. Trufanova ◽  
V. I. Yankov
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Numerical Analysis ◽  
Transfer Processes

scholarly journals Numerical Analysis and Modelling of Heat Transfer Processes through Perforated Clay Brick Masonry Walls

2017 ◽  
Vol 38 ◽  
pp. 492-499 ◽  
Author(s):  
G. Kanellopoulos ◽  
V.G. Koutsomarkos ◽  
K.J. Kontoleon ◽  
K. Georgiadis-Filikas
Keyword(s):  
Heat Transfer ◽  
Numerical Analysis ◽  
Brick Masonry ◽  
Masonry Walls ◽  
Clay Brick ◽  
Transfer Processes

scholarly journals Modeling of additive height and numerical analysis of cooling parameters for aero blade remanufacturing

2021 ◽  
Vol 12 (2) ◽  
pp. 803-818
Author(s):  
Miao Gong ◽  
Shijie Dai ◽  
Tao Wang ◽  
Liwen Wang
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Numerical Analysis ◽  
Cooling Effect ◽  
Transfer Model ◽  
Factors Affecting ◽  
Coupled Heat Transfer ◽  
Blade Repair ◽  
Geometric Morphology ◽  
The Mathematical Model

Abstract. Additive remanufacturing height and matching cooling parameters are the key factors affecting blade repair quality. First, the mathematical model of the single additive remanufacturing repair height and wire-feeding speed was established, the solution method was proposed and the numerical solution was obtained, and the validity of the model was verified by experiments. Then, based on the calculation results of a single additive remanufacturing repair, the geometric morphology of the cross section under double additive remanufacturing repair was analyzed, and the mathematical model was established. Second, based on the optimal parameters obtained by numerical analysis and the mathematical model, the fluid structure coupling heat transfer model of “blade fixture” for base channel cooling was established. The cooling effect of the typical section under different initial temperatures and different flow rates was calculated, and the coupled heat transfer in the process of blade remanufacturing was explained by the mechanism. Third, through the comparative analysis of the cooling effect, optimal cooling parameters of double additive remanufacturing repair were obtained, and the model of coupled heat flow was verified by experiment. The results showed that the mathematical model of additive remanufacturing height is effective for studying the thermal cycle and cooling effect of welding, and the cooling parameters obtained by numerical analysis can effectively guarantee the quality of double additive remanufacturing of blade repair.

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.

Heat Transfer under a Flow of the Highly Viscous Crude Oil in a Buried Oil Pipeline

2021 ◽  
Vol 107 ◽  
pp. 122-128
Author(s):  
Aidar Kadyirov ◽  
Julia Karaeva ◽  
Ekaterina Vachagina
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Temperature Distribution ◽  
Crude Oil ◽  
Air Temperature ◽  
High Viscosity ◽  
Numerical Calculations ◽  
Oil Pipeline ◽  
Transfer Processes ◽  
The Republic

The paper presents a mathematical model and the results of numerical calculations of heat transfer processes during the flow of highly viscous crude oil in an oil pipeline. Comparison with literature data is performed. The samples of oil from the field of the Republic of Tatarstan (Russia) that are characterized by high viscosity were considered as crude oil. The influence of air temperature on the temperature distribution in the soil was investigated. The analysis of the distribution of crude oil temperature along the length of the pipeline was carried out.

scholarly journals Numerical analysis of heat transfer in air-water heat exchanger with microchannel coil

2019 ◽  
Vol 95 ◽  
pp. 02004
Author(s):  
Vladimir Glazar ◽  
Anica Trp ◽  
Kristian Lenic ◽  
Fran Torbarina
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Fluid Flow ◽  
Heat Exchanger ◽  
Numerical Analysis ◽  
Flow Direction ◽  
Heat Fluxes ◽  
Experimental Investigations ◽  
Flow And Heat Transfer ◽  
Working Parameters

This paper presents numerical analysis of fluid flow and heat transfer in the heat exchanger with microchannel coil (MCHX). In accordance with previously published experimental results, 3D mathematical model has been defined and appropriate numerical simulation of heat transfer has been performed. Geometry and working parameters of cross-flow air-water heat exchanger with microchannel coil, installed in an open circuit wind tunnel and used in experimental investigations, have been applied in numerical analysis in order to validate the mathematical model. 3D model with air and water fluid flow and heat transfer domains has been used, as it gives more precise results compared to models that assume constant temperatures or constant heat fluxes on the pipe walls. Developed model comprised full length of air and water flows in the heat exchanger. Due to limitations of computational capacity, domain has been divided in multiple computational blocks in the water flow direction and then solved successively using CFD solver Fluent. Good agreement between experimentally measured and numerically calculated results has been obtained. The influence of various working parameters on heat transfer in air-water heat exchanger has been studied numerically, followed with discussion and final conclusions.

scholarly journals ДВУХТЕМПЕРАТУРНАЯ МАТЕМАТИЧЕСКАЯ МОДЕЛЬ ГИДРОАККУМУЛЯТОРА С ТЕПЛОВЫМ РЕГУЛИРОВАНИЕМ ДЛЯ УСЛОВИЙ НЕВЕСОМОСТИ

2020 ◽  
pp. 12-21
Author(s):  
Полина Сергеевна Коваль ◽  
Константин Сергеевич Епифанов ◽  
Рустем Юсуфович Турна
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Single Phase ◽  
Saturation Temperature ◽  
Heat Fluxes ◽  
Zero Gravity ◽  
Detailed Model ◽  
Conservation Equations ◽  
Transfer Processes ◽  
Two Temperature

It is advisable to use two-phase heat transfer circuits (TPC) on spacecraft with high heat release in thermal control systems (TCS). TPC has many advantages over single-phase heat transfer loops. In such circuits, heat is accumulated and transferred in the form of latent heat of vaporization. TPC can transfer a much larger amount of heat per unit mass flow rate, the temperature of objects can be maintained almost constant throughout the heat supply area and close to the saturation temperature. Besides, all heat transfer processes occurring during boiling are more intense than with conventional convective heat transfer. Therefore, the mass and dimensions of the TCS based on the TPC will be less than based on single-phase circuits. The thermally regulated pressure accumulator (HCA) is the most important element of the TPC. The article proposes a simplified two-temperature mathematical model for describing nonequilibrium heat-mass transfer processes in HCA under zero gravity. The mathematical model of the HCA is formed using the method of idealized elements. The authors detail the energy conservation equations for control volumes and thermal units, mass conservation equations, equations for heat fluxes and mass sweats. It allows you to quickly carry out the calculation and analyze an acceptable result for preliminary estimates. Previously, the authors published the work, which describes a detailed multi-temperature model that allows us to estimate the nonequilibrium in the liquid phase. A detailed model allows you to calculate almost any process in the HCA with fairly high accuracy, but the program is quite voluminous and the calculation takes a lot of time. Therefore, on the recommendation of the developers of the AMESim software package, the authors formed a simplified two-temperature nonequilibrium HCA model. The model is implemented in Fortran software and tested to establish a quasistationary regime and tested for thermal balance. Based on the data of a space experiment on heating HCA with ammonia, the estimated value of the convective component of heat transfer under zero gravity is estimated. This concept and model can be refined based on the actual design of the accumulator. For example, equations can be written for a cylindrical HCA, placing the heater on the surface of the housing or in the center, etc.

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