A Thermal Fluid Convection Model for the Fluid Cell Subject to the Transient Thermal Field

2006 ◽  
Author(s):  
Xiaoling He
Keyword(s):  
Thermal Field ◽  
Fluid Convection ◽  
Convection Model ◽  
Transient Thermal ◽  
Fluid Cell

scholarly journals Successive Bifurcation Conditions of a Lorenz-Type Equation for the Fluid Convection Due to the Transient Thermal Field

2007 ◽  
Vol 2007 ◽  
pp. 1-24 ◽  
Author(s):  
Xiaoling He
Keyword(s):  
Thermal Field ◽  
Type Equation ◽  
Bottom Plate ◽  
Transient Temperature ◽  
Type Model ◽  
Convection Flow ◽  
Parallel Plates ◽  
Fluid Properties ◽  
Fluid Convection ◽  
Transient Thermal

This paper investigates the convection flow between the two parallel plates in a fluid cell subject to the transient thermal field. We use the modal approximations similar to that of the original Lorenz model to obtain a generalized Lorenz-type model for the flow induced by the transient thermal field at the bottom plate. This study examines the convection flow bifurcation conditions in relation to the transient temperature variations and the flow properties. We formulated successive bifurcation conditions and illustrated the various flow behaviors and their steady-state attractors affected by the thermal field functions and fluid properties.

A Coupled Motion of the Thermally Induced Fluid Convection and the Membrane Motion

2008 ◽  
Vol 3 (3) ◽  
Author(s):  
Xiaoling He
Keyword(s):  
Thermal Field ◽  
Duffing Oscillator ◽  
Solid Material ◽  
Convection Flow ◽  
Thermally Induced ◽  
Flow Motion ◽  
Fluid Convection ◽  
The Difference ◽  
The Stability ◽  
Transient Thermal

The present study formulates a model for a coupled oscillation of the convective flow and the solid membrane vibration, which occurs in a 2D domain of a fluid cell. The convection flow is induced by the transient thermal field of the membrane at the bottom of the fluid. The heat conduction in the solid material also causes the membrane to vibrate. This flow motion deviates from the conventional Rayleigh–Benard problem in that a transient thermal field causes the convection flow instead of a constant temperature gradient. A numerical computation reveals the synchronized motion behaviors between the Lorenz-type oscillator for the convection flow and the Duffing oscillator for the membrane motion. The bifurcation conditions from the stability analysis of the model justify the steady-state attractor behaviors and the difference in behavior from the oscillators without coupling.

Geochemistry of syntectonic, crustal fluid regimes along the Lithoprobe Southern Canadian Cordillera Transect

1995 ◽  
Vol 32 (10) ◽  
pp. 1699-1719 ◽  
Author(s):  
Bruce E. Nesbitt ◽  
Karlis Muehlenbachs
Keyword(s):  
Deep Convection ◽  
Canadian Cordillera ◽  
Depth Of Penetration ◽  
Crustal Fluid ◽  
Quartz Veins ◽  
Economic Significance ◽  
Rock Types ◽  
Brittle Ductile Transition ◽  
Fluid Convection ◽  
Convection Model

In conjunction with the Lithoprobe southern Canadian Cordillera program, an extensive examination of geochemical indicators of origins, movement, chemical evolution, and economic significance of paleocrustal fluids was conducted. The study area covers approximately 360 000 km2from the Canadian Rockies to Vancouver Island. Research incorporated petrological, mineralogical, fluid-inclusion, δ18O, δD, δ13C, and Rb/Sr studies of samples of quartz ± carbonate veins and other rock types. The results of the study document a variety of pre-, syn-, and postorogenic, crustal fluid events. In the Rockies, a major pre-Laramide hydrothermal event was identified, which was comprised of a west to east migration of warm, saline brines. This was followed by a major circulation of meteoric water in the Rockies during Laramide uplift. In the southern Omineca extensional zone, convecting surface fluids penetrated to the brittle–ductile transition at 350–450 °C and locally into the underlying more ductile rocks. A principal conclusion of the study is that most quartz ± carbonate veins in metamorphic rocks in the southern Canadian Cordillera precipitated from deeply converted surface fluids. This conclusion supports a surface fluid convection model for the genesis of mesothermal Au–quartz veins, common in greenschist-facies rocks worldwide. The combination of our geochemical results with the results of other Lithoprobe studies indicates that widespread and deep convection of surface fluids in rocks undergoing active metamorphism is a commonplace phenomena in extensional settings, while in compressional-thrust settings the depth of penetration of surface fluids is more limited.

Electroelastic field in sheared piezoelectric bodies with D∞ symmetry disturbed by transient thermal field

2018 ◽  
Vol 41 (10-12) ◽  
pp. 1346-1363
Author(s):  
Masayuki Ishihara ◽  
Yuhei Uesugi ◽  
Yoshihiro Ootao ◽  
Yoshitaka Kameo
Keyword(s):  
Thermal Field ◽  
Electroelastic Field ◽  
Transient Thermal

scholarly journals Transient Thermal Field Analysis in ACCC Power Lines by the Green’s Function Method

Energies ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 280
Author(s):  
Jerzy Gołębiowski ◽  
Marek Zaręba
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Thermal Field ◽  
Continuity Condition ◽  
Field Analysis ◽  
Parabolic Differential Equations ◽  
Steady State Current ◽  
Core Line ◽  
Transient Thermal

The paper investigates the dynamics of the thermal field of the ACCC (aluminum conductor composite core) line. The system was heated by solar radiation and current flow. Conductor cooling was modeled using the total heat transfer coefficient as the sum of convective and radiative components. The temperature increase generated by the current is described by a system of parabolic differential equations with an appropriate set of boundary, initial and continuity condition. The mentioned boundary-initial problem was solved by a modified Green’s method, adapted to the layered structure of the system. For this purpose, Green’s functions, as the kernels of integral operators inverse to differential ones, were determined. Aluminum resistivity and heat transfer coefficient change significantly with temperature. For this reason, the solution to the problem is presented in the form of a lower and upper estimation of the heating curve and local time constant. A steady-state current rating was also determined. The results are presented graphically and verified by other methods (power balance and finite element). The physical interpretation of the presented solution is also given.

Thermal Analysis of the Mg-Al Alloys

2006 ◽  
Vol 508 ◽  
pp. 603-608 ◽  
Author(s):  
Jožef Medved ◽  
Primož Mrvar
Keyword(s):  
Numerical Simulation ◽  
Thermal Field ◽  
Crystalline Silicon ◽  
Al Alloys ◽  
Viscoplastic Deformation ◽  
Silicon Ingot ◽  
Cooling Conditions ◽  
Crystallisation Process ◽  
Transient Thermal

Multi-crystalline silicon ingot casting using directional crystallisation is the most costeffective technique for the production of Si for the photovoltaic industry. Non-uniform cooling conditions and a non-planarity of the solidification front result, however, in the build-up of stresses and viscoplastic deformation. Known defects, such as dislocations and residual stresses, can then occur and reduce the quality of the produced material. Numerical simulation, combined with experimental investigation, is therefore a key tool for understanding the crystallisation process, and optimizing it. The purpose of the present work is to present an experimental furnace for directional crystallisation of silicon, and its analysis by means of numerical simulation. The complete casting procedure, i.e., including both the crystallisation phase and the subsequent ingot cooling, is simulated. The thermal field has been computed by a CFD tool, taking into account important phenomena such as radiation and convection in the melt. The transient thermal field is used as input for a thermo-elasto-viscoplastic model for the analysis of stress build-up and viscoplastic deformation during the process. Numerical analysis is employed to identify process phases where further optimisation is needed in order to reduce generated defects.

scholarly journals Thermal Field Analysis and Simulation of an Infrared Belt Furnace Used for Solar Cells

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Bai Lu ◽  
Liang Zongcun ◽  
Shen Hui
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Gas Flow ◽  
Thermal Field ◽  
Field Analysis ◽  
Metal Particles ◽  
Thermal Fields ◽  
Internal Structures ◽  
Cell Firing ◽  
Transient Thermal

During solar cell firing, volatile organic compounds (VOC) and a small number of metal particles were removed using the gas flow. When the gas flow was disturbed by the thermal field of infrared belt furnace and structure, the metal particles in the discharging gas flow randomly adhered to the surface of solar cell, possibly causing contamination. Meanwhile, the gas flow also affected the thermal uniformity of the solar cell. In this paper, the heating mechanism of the solar cell caused by radiation, convection, and conduction during firing was analyzed. Afterward, four 2-dimensional (2D) models of the furnace were proposed. The transient thermal fields with different gas inlets, outlets, and internal structures were simulated. The thermal fields and the temperature of the solar cell could remain stable and uniform when the gas outlets were installed at the ends and in the middle of the furnace, with the gas inlets being distributed evenly. To verify the results, we produced four types of furnaces according to the four simulated results. The experimental results indicated that the thermal distribution of the furnace and the characteristics of the solar cells were consistent with the simulation. These experiments improved the efficiency of the solar cells while optimizing the solar cell manufacturing equipment.

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