scholarly journals Implementation of Surface Radiation and Fluid-Structure Thermal Coupling in Atmospheric Reentry

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Ojas Joshi ◽  
Pénélope Leyland
Keyword(s):  
Numerical Simulation ◽  
Radiative Heating ◽  
Surface Radiation ◽  
Radiative Cooling ◽  
Thermal Coupling ◽  
Total Heat Flux ◽  
Hollow Cone ◽  
Atmospheric Reentry ◽  
Thermal Fields ◽  
Flap Region

During atmospheric reentry, radiative heating is one of the most important component of the total heat flux. In this paper, we investigate how the thermal radiation coming from the postshock region interacts with the spacecraft structure. A model that takes into account the radiation reflected by the surface is developed and implemented in a solid solver. A partitioned algorithm performs the coupling between the fluid and the solid thermal fields. Numerical simulation of a hollow cone head and a deployed flap region shows the effects of the radiative cooling and the significance of the surface radiation.

scholarly journals The Strengthening Relationship between Eurasian Snow Cover and December Haze Days in Central North China after the Mid-1990s

2017 ◽  
Author(s):  
Zhicong Yin ◽  
Huijun Wang
Keyword(s):  
Soil Moisture ◽  
Snow Cover ◽  
North China ◽  
Surface Wind ◽  
Surface Radiation ◽  
Radiative Cooling ◽  
Atmospheric Circulations ◽  
Haze Pollution ◽  
The Relationship ◽  
Haze Days

Abstract. The haze pollution in December has become increasingly serious over recent decades and imposes damage on society, ecosystems, and human health. In addition to anthropogenic emissions, climate change and variability were conducive to haze in China. In this study, the relationship between the snow cover over East Europe and West Siberia (SCES) and the number of haze days in December in central North China was analyzed. This relationship significantly strengthened after the mid-1990s, which is attributed to the effective connections between the SCES and the Eurasian atmospheric circulations. During 1998–2016, the SCES significantly influenced the soil moisture and land surface radiation, and then, the combined underlying drivers of enhanced soil moisture and radiative cooling moved the East Asia jet stream northward and induced anomalous, anti-cyclonic circulation over central North China. Modulated by such atmospheric circulations, the local lower boundary layer, the decreased surface wind and the more humid air were conducive to the worsening dispersion conditions and frequent haze occurrences. In contrast, from 1979 to 1997, the linkage between the SCES and soil moisture was negligible. Furthermore, the correlated radiative cooling was distributed narrowly and far from the key area of snow cover. The associated atmospheric circulations with the SCES were not significantly linked with the ventilation conditions over central North China. Consequently, the relationship between the SCES and the number of hazy days in central North China was insignificant before the mid-1990s but has strengthened and has become significant since then.

scholarly journals Numerical Simulation of Thawing Process in Frozen Soil

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Zhaoyu Yan ◽  
Wei Pan ◽  
Junjie Fang ◽  
Zihui Liu
Keyword(s):  
Numerical Simulation ◽  
Heat Flux ◽  
Liquid Water ◽  
Minimum Temperature ◽  
Frozen Soil ◽  
Total Heat ◽  
Water Volume ◽  
Total Heat Flux ◽  
Volume Curve ◽  
Thawing Process

Permafrost has been thawing faster due to climate change which would release greenhouse gases, change the hydrological regimes, affect buildings above, and so on. It is necessary to study the thawing process of frozen soil. A water-heat coupling model for frozen soil thawing is established on Darcy’s law and Heat Transfer in Porous Media interfaces in Comsol Multiphysics 5.5. Three curves of total liquid water volume, minimum temperature, and total heat flux in the thawing process are obtained from a numerical simulation. The distributions of liquid water, temperature, and pressure based on time are simulated too. The liquid water distribution is consistent with the total liquid water volume curve. The temperature distribution is confirmed by the minimum temperature and total heat flux curve. The pressure distribution represents ice in the frozen soil that generates negative pressure during the melting process. The numerical simulation research in this article deepens the understanding of the internal evolution in the process of frozen soil thawing and has a certain reference value for subsequent experimental research and related applications.

scholarly journals Numerical Simulation of High Mach Number Astrophysical Jets with Radiative Cooling

2005 ◽  
Vol 24 (1) ◽  
pp. 29-44 ◽  
Author(s):  
Youngsoo Ha ◽  
Carl L. Gardner ◽  
Anne Gelb ◽  
Chi-Wang Shu
Keyword(s):  
Numerical Simulation ◽  
Mach Number ◽  
Radiative Cooling ◽  
Astrophysical Jets ◽  
High Mach Number ◽  
High Mach

Simulation Study on the Radiant Tube Installation Height for the Gas-Infrared Heated System

2012 ◽  
Vol 614-615 ◽  
pp. 239-244
Author(s):  
Da Ying Zhang ◽  
Wei Dong Zhuang ◽  
Ke Qin Gong
Keyword(s):  
Numerical Simulation ◽  
Heat Flux ◽  
Numerical Calculation ◽  
Radiation Flux ◽  
Heat Radiation ◽  
Total Heat Flux ◽  
Tube Surface ◽  
Indoor Temperature ◽  
Radiant Tube ◽  
Average Temperature

The numerical simulation for radiant tube heat transferring process of the gas-infrared heated room was finished. By means of numerical calculation, the influences of radiant tube installation height to the indoor temperature and workspace air temperature as well as the heat radiation flux were studied. The results show: The greater of radiant tube surface installation height, The lower of the workspace average temperature, average radiation temperature and radiant tube total heat flux.

NUMERICAL SIMULATION OF THE RADIATIVE HEATING OF A MOVING SHEET

2004 ◽  
Vol 47 (1) ◽  
pp. 1-25 ◽  
Author(s):  
Sandra K. S. Boetcher ◽  
Ephraim M. Sparrow ◽  
John P. Abraham
Keyword(s):  
Numerical Simulation ◽  
Radiative Heating
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