Transient Numerical Simulation of Linear Thermal Transmittance in Software CalA

2014 ◽  
Vol 1041 ◽  
pp. 277-280 ◽  
Author(s):  
Josef Plášek ◽  
Ondřej Šikula
Keyword(s):  
Numerical Simulation ◽  
Complex Geometry ◽  
Detailed Calculation ◽  
Variable Boundary ◽  
Thermal Transmittance ◽  
3D Geometry ◽  
Steady Heat Conduction ◽  
Steady Heat ◽  
Variable Boundary Conditions ◽  
Transient Numerical Simulation

Calculation of heat losses of buildings according to European standard EN ISO 10211 and Czech standard ČSN 73 0540 is simplified to one-dimensional time-steady heat conduction through the building construction in direction of the largest temperature gradient. This simplification of the calculation is incorrect in case of complex geometry. Calculation according to norm takes into account this inaccuracy and uses Linear Thermal Transmittance Ψ [W/(m·K)] in 2D geometry or Point Thermal Transmittance χ [W/(m2·K)] in the 3D geometry as a calculation correction. This contribution is focused on detailed calculation of linear thermal transmittance in case of contact external peripheral wall and plastic window frame. Results of two-dimensional transient numerical simulation show unsteady linear thermal transmittance in time and dependence on solar radiation. All of these variable boundary conditions can be easily simulated in the software CalA as well as complex geometry.

scholarly journals Direct Numerical Simulation of Pore-Scale Trapping Events During Capillary-Dominated Two-Phase Flow in Porous Media

2021 ◽  
Author(s):  
Mosayeb Shams ◽  
Kamaljit Singh ◽  
Branko Bijeljic ◽  
Martin J. Blunt
Keyword(s):  
Numerical Simulation ◽  
Porous Media ◽  
Direct Numerical Simulation ◽  
Complex Geometry ◽  
Flow In Porous Media ◽  
Pore Scale ◽  
Contact Lines ◽  
Two Phase ◽  
X Ray ◽  
Aspect Ratios

AbstractThis study focuses on direct numerical simulation of imbibition, displacement of the non-wetting phase by the wetting phase, through water-wet carbonate rocks. We simulate multiphase flow in a limestone and compare our results with high-resolution synchrotron X-ray images of displacement previously published in the literature by Singh et al. (Sci Rep 7:5192, 2017). We use the results to interpret the observed displacement events that cannot be described using conventional metrics such as pore-to-throat aspect ratio. We show that the complex geometry of porous media can dictate a curvature balance that prevents snap-off from happening in spite of favourable large aspect ratios. We also show that pinned fluid-fluid-solid contact lines can lead to snap-off of small ganglia on pore walls; we propose that this pinning is caused by sub-resolution roughness on scales of less than a micron. Our numerical results show that even in water-wet porous media, we need to allow pinned contacts in place to reproduce experimental results.

3-D Steady Heat Conduction Solver via Deep Learning

2021 ◽  
pp. 1-1
Author(s):  
Yinpeng Wang ◽  
Jianmei Zhou ◽  
Qiang Ren ◽  
Yaoyao Li ◽  
Donglin Su
Keyword(s):  
Deep Learning ◽  
Heat Conduction ◽  
Steady Heat Conduction ◽  
Steady Heat

scholarly journals Numerical Simulation Study on the Front Shape and Thermal Stresses in Growing Multicrystalline Silicon Ingot: Process and Structural Design

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1053
Author(s):  
Chengmin Chen ◽  
Guangxia Liu ◽  
Lei Zhang ◽  
Guodong Wang ◽  
Yanjin Hou ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Thermal Stress ◽  
Thermal Stresses ◽  
Simulation Method ◽  
Power Ratio ◽  
Radial Temperature ◽  
Front Shape ◽  
Simulation Results ◽  
Insulation Block ◽  
Transient Numerical Simulation

In this paper, a transient numerical simulation method is used to investigate the effects of the two furnace configurations on the thermal field: the shape of the melt–crystal (M/C) interface and the thermal stress in the growing multicrystalline ingot. First, four different power ratios (top power to side power) are investigated, and then three positions (i.e., the vertical, angled, and horizontal positions) of the insulation block are compared with the conventional setup. The power ratio simulation results show that with a descending power ratio, the M/C interface becomes flatter and the thermal stress in the solidified ingot is lower. In our cases, a power ratio of 1:3–1:4 is more feasible for high-quality ingot. The block’s position simulation results indicate that the horizontal block can more effectively reduce the radial temperature gradient, resulting in a flatter M/C interface and lower thermal stress.

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