View Factor Catalogue

This paper refers to a numerical study of the hypo-thermal behaviour of a pine tree in a forest fire environment. The pine tree thermal response numerical model is based on energy balance integral equations for the tree elements and mass balance integral equation for the water in the tree. The simulation performed considers the heat conduction through the tree elements, heat exchanges by convection between the external tree surfaces and the environment, heat exchanges by radiation between the flame and the external tree surfaces and water heat loss by evaporation from the tree to the environment. The virtual three-dimensional tree model has a height of 7.5 m and is constituted by 8863 cylindrical elements representative of its trunks, branches and leaves. The fire front has 10 m long and a 2 m high. The study was conducted taking into account that the pine tree is located 5, 10 or 15 m from the fire front. For these three analyzed distances, the numerical results obtained regarding to the distribution of the view factors, mean radiant temperature and surface temperatures of the pine tree are presented. As main conclusion, it can be stated that the values of the view factor, MRT and surface temperatures of the pine tree decrease with increasing distance from the pine tree in front of fire.

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From Resistance to Digital Technologies in the Context of the Reaction to Distance Learning in the School Context during COVID-19

Education Sciences ◽

10.3390/educsci11040163 ◽

2021 ◽

Vol 11 (4) ◽

pp. 163

Author(s):

Giusi Antonia Toto ◽

Pierpaolo Limone

Keyword(s):

Distance Learning ◽

School Context ◽

Digital Technologies ◽

Point Of View ◽

View Factor ◽

Regression Analyses ◽

Teachers Perceptions ◽

Professional Perception ◽

The Relationship ◽

Professional Perceptions

In the relationship between teachers and distance learning in the context of COIVD-19, a series of unprecedented dynamics have emerged relating to a process of open-air experimentation that is going on in the world of school. The main constructs investigated in this paper concern the professional perceptions of teachers in terms of their skills and resistances towards digital technologies. To investigate this topic, a questionnaire on distance learning was administered to a sample of 658 teachers. From a methodological point of view, factor and reliability analyses and correlation and regression analyses were conducted. From the analysis of the results, it emerged that the questionnaire measures the resistance of teachers to distance learning and focuses on three main dimensions (two positive and one negative) that link teachers’ perceptions to the resistance to distance learning. In conclusion, the theme of the acceptance of technologies in the practice of teachers is still a subject full of meaning for professional perception and vision. A second issue concerns precisely the relationship between digital technologies and users, which must no longer focus only on the relationship with students but also on the perspective of the other training actors, including teachers.

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Positional error modeling of sky‐view factor measurements within urban street canyons

Transactions in GIS ◽

10.1111/tgis.12761 ◽

2021 ◽

Author(s):

Zian Wang ◽

Guoan Tang ◽

Guonian Lü ◽

Cheng Ye ◽

Fangzhuo Zhou ◽

...

Keyword(s):

Error Modeling ◽

View Factor ◽

Positional Error ◽

Street Canyons ◽

Urban Street ◽

Sky View Factor ◽

Urban Street Canyons

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Contactless and spatially structured cooling by directing thermal radiation

Scientific Reports ◽

10.1038/s41598-021-95606-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Nicola M. Kerschbaumer ◽

Stefan Niedermaier ◽

Theobald Lohmüller ◽

Jochen Feldmann

Keyword(s):

Thermal Radiation ◽

Radiative Heat ◽

Radiative Cooling ◽

View Factor ◽

Temperature Pattern ◽

Thermal Gradients ◽

Science And Engineering ◽

Building Management ◽

Temperature Manipulation ◽

Novel Concept

AbstractIn recent years, radiative cooling has become a topic of considerable interest for applications in the context of thermal building management and energy saving. The idea to direct thermal radiation in a controlled way to achieve contactless sample cooling for laboratory applications, however, is scarcely explored. Here, we present an approach to obtain spatially structured radiative cooling. By using an elliptical mirror, we are able to enhance the view factor of radiative heat transfer between a room temperature substrate and a cold temperature landscape by a factor of 92. A temperature pattern and confined thermal gradients with a slope of ~ 0.2 °C/mm are created. The experimental applicability of this spatially structured cooling approach is demonstrated by contactless supercooling of hexadecane in a home-built microfluidic sample. This novel concept for structured cooling yields numerous applications in science and engineering as it provides a means of controlled temperature manipulation with minimal physical disturbance.

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Calculation of the irradiance of solar radiation in a greenhouse with a complex structure using a diagram for sky view factor

Journal of Agricultural Meteorology ◽

10.2480/agrmet.d-19-00043 ◽

2020 ◽

Vol 76 (1) ◽

pp. 44-52

Author(s):

Shuh MATSUDA ◽

Hisashi YOSHIKOSHI ◽

Tomoyo SUZUKI ◽

Yuuki OHTA ◽

Ayaka CHIBA ◽

...

Keyword(s):

Solar Radiation ◽

Complex Structure ◽

View Factor ◽

Sky View Factor

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Development of synthetic hemispheric projections suitable for assessing the sky view factor on vertical planes

Renewable Energy ◽

10.1016/j.renene.2014.08.025 ◽

2015 ◽

Vol 74 ◽

pp. 279-286 ◽

Cited By ~ 5

Author(s):

J. Ramírez-Faz ◽

R. López-Luque ◽

F.J. Casares

Keyword(s):

View Factor ◽

Sky View Factor

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Analysis of the Influence of Sky View Factor on Urban Surface Temperature Based on Multi-Source Data

10.1109/igarss47720.2021.9553054 ◽

2021 ◽

Author(s):

Qianhao Cheng ◽

Qiang Chen ◽

Yuanyuan Li ◽

Beilei Cao

Keyword(s):

Surface Temperature ◽

Urban Surface ◽

View Factor ◽

Sky View Factor ◽

Source Data

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A Study of Heat Transfer Calculation Method of Reactor Vessel Metallic Insulation

Volume 1: Plant Operations, Maintenance, Engineering, Modifications, Life Cycle and Balance of Plant; Nuclear Fuel and Materials; Plant Systems, Structures and Components; Codes, Standards, Licensing and Regulatory Issues ◽

10.1115/icone22-30446 ◽

2014 ◽

Author(s):

Yan Dapeng ◽

Ying Luo

Keyword(s):

Heat Transfer ◽

Computational Model ◽

Complex Geometry ◽

Effective Conductivity ◽

Radiation Heat Transfer ◽

Reactor Vessel ◽

View Factor ◽

Main Mode ◽

Modified Model ◽

Test Result

Metallic insulation is commonly used in reactor vessel because of its resistance to radiation and corrosion. Since the main mode of heat loss of reactor vessel is thermal radiation, the ability to prevent radiation heat transfer is important for metallic insulation. But the thermal conductivity of metallic insulation is difficult to calculate owing to their complex geometry. This article uses FLUENT 14.0 to obtain the important parameter “view factor”, and then develops a computational model of effective conductivity of metallic insulation. Heat transfer test of metallic insulation was done, and the numerical simulation of metallic insulation was also performed. Based on results of test and simulation, the computational model is modified. The modified model can fit the test result better. Based on the modified model, the effective conductivity of metallic insulation increases with the increase of temperature of hot side and cold side, among which the temperature of hot side influences more. And when the temperature is high, the effective conductivity increases much faster.

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