scholarly journals Computer simulations of thermal phenomena in surface heating process using the real distribution of Yb:YAG laser power

2018 ◽  
Vol 157 ◽  
pp. 02021
Author(s):  
Marcin Kubiak ◽  
Vladimír Dekýš ◽  
Tomasz Domański ◽  
Pavol Novák ◽  
Zbigniew Saternus
Keyword(s):  
Temperature Field ◽  
Fusion Zone ◽  
Computer Simulations ◽  
Cross Sections ◽  
Power Distribution ◽  
Laser Heating ◽  
Laser Power ◽  
Numerical Algorithms ◽  
Heating Process ◽  
Thermal Phenomena

This work concerns mathematical and numerical modelling of temperature field during Yb:YAG laser heating of sheets made of S355 steel with the motion of liquid steel in the fusion zone taken into account. Laser power distribution and the caustics are determined on the basis of the geostatistical kriging method. Temperature field and melted material velocity field in the fusion zone are obtained from the numerical solution of continuum mechanics equations using projection method and finite volume method. Numerical algorithms are implemented into computer solver using ObjectPascal programming language. Computer simulations of Yb:YAG laser heating process are performed for different process parameters. Characteristic zones of experimentally obtained cross sections of heated elements are compared to numerically predicted fusion zone and heat affected zone.

Simulation and Optimization of Temperature Field of Tank Cover with Super Large Diameter during the Creep Aging Forming Process

2021 ◽  
Vol 315 ◽  
pp. 3-9
Author(s):  
Yuan Gao ◽  
Li Hua Zhan ◽  
Hai Long Liao ◽  
Xue Ying Chen ◽  
Ming Hui Huang
Keyword(s):  
Temperature Field ◽  
Field Distribution ◽  
Temperature Difference ◽  
Single Stage ◽  
Maximum Temperature ◽  
Heating Process ◽  
Temperature Field Distribution ◽  
Two Stage ◽  
Maximum Temperature Difference ◽  
Forming Accuracy

The uniformity of temperature field distribution in creep aging process is very important to the forming accuracy of components. In this paper, the temperature field distribution of 2219 aluminum alloy tank cover during aging forming is simulated by using the finite element software FLUENT, and a two-stage heating process is proposed to reduce the temperature field distribution heterogeneity. The results show that the temperature difference of the tank cover is large in the single-stage heating process, and the maximum temperature difference is above 27°C,which seriously affects the forming accuracy of the tank cover. With two-stage heating process, the temperature difference in the first stage has almost no direct impact on the forming accuracy of the top cover. In the second stage, the temperature difference of the tank cover is controlled within 10°C, compared with the single-stage heating, the maximum temperature difference is reduced by more than 17°C. The two-stage heating effectively reduces the heterogeneity of the temperature field of the top cover. The research provides technical support for the precise thermal mechanical coupling of large-scale creep aging forming components.

The Numerical Analysis of Temperature Field During Moveable Induction Heating of Steel Plate

2012 ◽  
Vol 28 (02) ◽  
pp. 73-81
Author(s):  
Xue-biao Zhang ◽  
Yu-long Yang ◽  
Yu-jun Liu
Keyword(s):  
Temperature Field ◽  
Steady State ◽  
Numerical Model ◽  
Induction Heating ◽  
Temperature Difference ◽  
Steel Plate ◽  
Heating Process ◽  
Quasi Steady State ◽  
Initial State ◽  
Plate Temperature

In shipyards, hull curved plate formation is an important stage with respect to productivity and accuracy control of curved plates. Because the power and its distribution of induction heat source are easier to control and reproduce, induction heating is expected to be applied in the line heating process. This paper studies the moveable induction heating process of steel plate and develops a numerical model of electromagneticthermal coupling analysis and the numerical results consistent with the experimental results. The numerical model is used to analyze the temperature changing rules and the influences on plate temperature field of heating speed of moveable induction heating of steel plate, and the following conclusions are drawn. First, the process of moveable induction heating of steel plate can be divided into three phases of initial state, quasi-steady state, and end state. The temperature difference between the top and bottom surfaces of the steel plate at the initial state is the biggest; it remains unchanged at the quasi-steady state and it is the smallest at the end state. Second, obvious end effect occurs when the edges of the steel plate are heated by the inductor, which causes a decrease in temperature difference between the top and bottom surfaces of the steel plate that is unfavorable for formation of pillow shape plates. Third, with the increase of heating speed, the temperature difference between the top and bottom surfaces of the steel plate increases gradually.

scholarly journals Analysis of spatial thermal field in a magnetic bearing

Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 52-56
Author(s):  
Dawid Wajnert ◽  
Bronisław Tomczuk
Keyword(s):  
Temperature Field ◽  
Mathematical Models ◽  
Computer Simulations ◽  
Thermal Field ◽  
Three Dimensional ◽  
Magnetic Bearing ◽  
Field Analysis ◽  
Two Dimensional ◽  
Temperature Distributions ◽  
Dimensional Simulation

AbstractThis paper presents two mathematical models for temperature field analysis in a new hybrid magnetic bearing. Temperature distributions have been calculated using a three dimensional simulation and a two dimensional one. A physical model for temperature testing in the magnetic bearing has been developed. Some results obtained from computer simulations were compared with measurements.

3D Modeling of the Thermal Phenomena During Laser Melting of Polymers

2018 ◽  
Author(s):  
Aoulaiche Mokrane ◽  
M’hamed Boutaous ◽  
Shihe Xin ◽  
Dennis Siginer
Keyword(s):  
Laser Energy ◽  
Selective Laser Sintering ◽  
Heating Process ◽  
Numerical Resolution ◽  
Laser Absorption ◽  
Fortran Code ◽  
Proposed Model ◽  
Multiphysics Coupling ◽  
Modeling Data ◽  
Thermal Phenomena

A comprehensive model of the selective laser sintering (SLS) process at the scale of the part is presented for application to polymeric powders. The powder bed is considered as a continuous medium with homogenized properties. A thermal model with detailed multiphysics coupling is presented. The model accounts for all elements of the thermal history : laser absorption, melting, coalescence, densification and volume shrinkage. For numerical resolution, a 3D in-house fortran code using FV method is developed. The proposed model is validated through the comparison of modeling data with experimental results available in the published literature. A parametric analysis about the thermal efficiency of the heating process against the laser energy input is proposed and the influence on the densification and thermal kinetics is discussed with regarding the evolution of the structure of the material.

Key Technology Research on Mould Heating System of Injecting Machine

2010 ◽  
Vol 97-101 ◽  
pp. 3579-3582
Author(s):  
Jin Guo Li ◽  
Lin Kang
Keyword(s):  
Power Distribution ◽  
Thermal Field ◽  
Design Method ◽  
Heating System ◽  
Field Analysis ◽  
Heating Process ◽  
Technology Research ◽  
Hot Plate ◽  
Plate Temperature ◽  
Control Precision

Effective calculated method of temperature field analysis was studied on the hot plate by CAE technologies. It provides design method and heating process for the mold. According to the specificity of hot plate, reasonable location of the thermocouple is discussed, power distribution and layout are designed, heating process of the hot plate is studied, so that hot plate temperature reaches the specified temperature and distributes. Feasible scheme has been got by computer simulation and the result is verified by experiment. The two problems of the temperature control precision and surface thermal field has been solved.

scholarly journals Comparative Neutronics Analysis of DIMPLE S06 Criticality Benchmark with Contemporary Reactor Core Analysis Computer Code Systems

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Wonkyeong Kim ◽  
Jinsu Park ◽  
Tomasz Kozlowski ◽  
Hyun Chul Lee ◽  
Deokjung Lee
Keyword(s):  
Comparative Analysis ◽  
Cross Sections ◽  
Power Distribution ◽  
Reactor Core ◽  
Computer Code ◽  
Anisotropic Scattering ◽  
Monte Carlo Code ◽  
Core Analysis ◽  
Modeling Approach ◽  
Significant Difference

A high-leakage core has been known to be a challenging problem not only for a two-step homogenization approach but also for a direct heterogeneous approach. In this paper the DIMPLE S06 core, which is a small high-leakage core, has been analyzed by a direct heterogeneous modeling approach and by a two-step homogenization modeling approach, using contemporary code systems developed for reactor core analysis. The focus of this work is a comprehensive comparative analysis of the conventional approaches and codes with a small core design, DIMPLE S06 critical experiment. The calculation procedure for the two approaches is explicitly presented in this paper. Comprehensive comparative analysis is performed by neutronics parameters: multiplication factor and assembly power distribution. Comparison of two-group homogenized cross sections from each lattice physics codes shows that the generated transport cross section has significant difference according to the transport approximation to treat anisotropic scattering effect. The necessity of the ADF to correct the discontinuity at the assembly interfaces is clearly presented by the flux distributions and the result of two-step approach. Finally, the two approaches show consistent results for all codes, while the comparison with the reference generated by MCNP shows significant error except for another Monte Carlo code, SERPENT2.

Size Effects on Nonequilibrium Laser Heating of Metal Films

1993 ◽  
Vol 115 (4) ◽  
pp. 842-847 ◽  
Author(s):  
T. Q. Qiu ◽  
C. L. Tien
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Effective Thermal Conductivity ◽  
Size Effects ◽  
Laser Heating ◽  
Energy Exchange ◽  
Short Pulse ◽  
Heating Process ◽  
Metal Thin Films ◽  
Short Pulse Laser

Picosecond and sub-picosecond lasers have become important tools in the fabrication and study of microstructures. When the laser pulse duration becomes comparable with or less than the characteristic time of energy exchange among microscopic energy carriers, the excited carriers are no longer in thermal equilibrium with the other carriers, creating a nonequilibrium heating situation. The presence of interfaces in metals provides additional scattering processes for electrons, which in turn affects the nonequilibrium heating process. This work studies size effects, due to both surface scattering and grain-boundary scattering, on the thermal conductivity and the energy exchange between electrons and the material lattice. A simple formula is established to predict the influence of film thickness, grain size, interface scattering parameters, and the electron and lattice temperatures on the effective thermal conductivity of metal thin films. Predictions of the analysis agree with the available experimental data. A three-energy-level model is developed to characterize the energy exchange between electrons and the lattice. This study shows that the size effect reduces the effective thermal conductivity and increases the electron-phonon energy exchange rate. The results are useful for improving processing quality, interpreting diagnostic results, and preventing thermal damage of thin films during short-pulse laser heating.

Sign in / Sign up

Export Citation Format

Share Document