Quantitative assessment of an integrated hydrodynamic thermal-capillary model for large-diameter Czochralski growth of silicon: comparison of predicted temperature field with experiment

1993 ◽  
Vol 126 (2-3) ◽  
pp. 413-434 ◽  
Author(s):  
T.A. Kinney ◽  
D.E. Bornside ◽  
R.A. Brown ◽  
K.M. Kim
2018 ◽  
Vol 2018 ◽  
pp. 1-16
Author(s):  
Liang Zhao ◽  
Zhiyong Yang ◽  
Lijie Wang

There is a growing demand for silos with large diameters and volumes; hence, the stresses induced by the temperature differences between the inner and the outer surfaces of the concrete walls of the large silos become significant. Sunshine is the main source of the temperature differences; and it is necessary to investigate the influences of sunshine on large concrete silos and ensure their safety and durability. In this paper, the temperature distribution of a concrete silo exposed to the sunshine was measured on site. A finite element (FE) model was built to analyze the temperature distribution under the sunshine, and the FE model was validated by comparing the yielded temperature field with that obtained on site. Based on the temperature field yielded in the FE model, the internal forces of the silo were determined by performing a structural analysis. After that, the FE model was extended and used for a parametrical study, and the influences induced by the factors like meteorological parameters, dimension of silos, and reference temperature on the temperature effects of the silo were investigated. The simulation results showed that the temperature gradient exhibited significant nonlinearities along the wall thickness. The performance of a steady-state analytical method was evaluated, which is conventionally used for the design of silos. It was found that, for the silos with the thicknesses of more than 30 centimeters, the steady-state method overestimated the temperature effects. It is suggested here that nonlinear temperature gradients should be employed for considering the temperature effects of large silos.


1974 ◽  
Vol 24-25 ◽  
pp. 432-436 ◽  
Author(s):  
C.D. Brandle ◽  
D.C. Miller

2006 ◽  
Vol 287 (2) ◽  
pp. 300-304 ◽  
Author(s):  
J. Luo ◽  
D. Shah ◽  
C.F. Klemenz ◽  
M. Dudley ◽  
H. Chen

1984 ◽  
Vol 70 (1-2) ◽  
pp. 169-178 ◽  
Author(s):  
A.Grant Elliot ◽  
Chia-Li Wei ◽  
Ray Farraro ◽  
Geoffrey Woolhouse ◽  
Martin Scott ◽  
...  

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Lei Hu ◽  
Shumin Yu ◽  
Qunshuang Ma ◽  
Bing Cui ◽  
Zhenyu Zhang ◽  
...  

Abstract Local postweld heat treatment (PWHT) is usually employed in field fabrication of large-sized ASME SA-335 Grade P92 steel pipes. Internal air flow in pipes that arise from field fabrication can result in considerable convection losses on the inside surface of the pipe when the pipe is not strictly sealed off. Welding and local PWHT experiments of a large diameter P92 steel pipe were conducted both with and without internal air flow, and temperature field of both sides of the pipe was measured. The conjugate heat transfer between the pipe and the internal air is simulated using computational fluid dynamics (CFD) method. The effect of internal air flow on temperature field was further investigated. Results indicate that temperature gradient along through-thickness direction and axial direction during local PWHT is significantly increased due to internal air flow. The increasing rate of temperature difference between inner and outer surface at weld centerline to internal air velocity is about 14.5 °C/(m s−1). The maximum temperature is no longer located at the weld centerline, which will lead to a risk of overheating. The temperature drop is severer in the air inlet side than air outlet side at same distance from weld centerline. For local PWHT to be successful, the internal air flow should be strictly limited during local PWHT; otherwise, the width of heated band (HB) should be extended.


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