Computational modeling and analysis of thermal characteristics of a rotating spacecraft subjected to solar radiation

2011 ◽  
Vol 40 (7) ◽  
pp. 655-676 ◽  
Author(s):  
Mohamed A. Gadalla ◽  
Essam Wahba
Keyword(s):  
Solar Radiation ◽  
Computational Modeling ◽  
Thermal Characteristics ◽  
Modeling And Analysis

scholarly journals Electrothermal Modeling and Analysis of Gallium Oxide Power Switching Devices

2019 ◽  
Author(s):  
Ramchandra M. Kotecha ◽  
Andriy Zakutayev ◽  
Wyatt K. Metzger ◽  
Paul Paret ◽  
Gilberto Moreno ◽  
...  
Keyword(s):  
Finite Element ◽  
Power Electronics ◽  
Gallium Oxide ◽  
Short Circuit ◽  
Thermal Characteristics ◽  
Wide Band ◽  
Element Model ◽  
Oxide Semiconductor ◽  
Modeling And Analysis ◽  
Device Architecture

Abstract Gallium oxide is an emerging wide band-gap material that has the potential to penetrate the power electronics market in the near future. In this paper, a finite-element gallium oxide semiconductor model is presented that can predict the electrical and thermal characteristics of the device. The finite element model of the two-dimensional device architecture is developed inside the Sentaurus environment. A vertical FinFET device architecture is employed to assess the device’s behavior and its static and dynamic characteristics. Enhancement-mode device operation is realized with this type of device architecture without the need for any selective area doping. The dynamic thermal behavior of the device is characterized through its short-circuit behavior. Based on the device static and dynamic behavior, it is envisioned that reliable vertical transistors can be fabricated for the power electronics applications.

scholarly journals Distinguishing ice-rich and ice-poor permafrost to map ground temperatures and ground ice occurrence in the Swiss Alps

2019 ◽  
Vol 13 (7) ◽  
pp. 1925-1941 ◽  
Author(s):  
Robert Kenner ◽  
Jeannette Noetzli ◽  
Martin Hoelzle ◽  
Hugo Raetzo ◽  
Marcia Phillips
Keyword(s):  
Solar Radiation ◽  
Thermal Characteristics ◽  
Mapping Method ◽  
Swiss Alps ◽  
Ground Ice ◽  
Climate Conditions ◽  
Distribution Maps ◽  
Ground Temperatures ◽  
Incoming Solar Radiation ◽  
Gravitational Processes

Abstract. Mountain permafrost is invisible, and mapping it is still a challenge. Available permafrost distribution maps often overestimate the permafrost extent and include large permafrost-free areas in their permafrost zonation. In addition, the representation of the lower belt of permafrost consisting of ice-rich features such as rock glaciers or ice-rich talus slopes can be challenging. These problems are caused by considerable differences in genesis and thermal characteristics between ice-poor permafrost, occurring for example in rock walls, and ice-rich permafrost. While ice-poor permafrost shows a strong correlation of ground temperature with elevation and potential incoming solar radiation, ice-rich ground does not show such a correlation. Instead, the distribution of ice-rich ground is controlled by gravitational processes such as the relocation of ground ice by permafrost creep or by ground ice genesis from avalanche deposits or glacierets covered with talus. We therefore developed a mapping method which distinguishes between ice-poor and ice-rich permafrost and tested it for the entire Swiss Alps. For ice-poor ground we found a linear regression formula based on elevation and potential incoming solar radiation which predicts borehole ground temperatures at multiple depths with an accuracy higher than 0.6 ∘C. The zone of ice-rich permafrost was defined by modelling the deposition zones of alpine mass wasting processes. This dual approach allows the cartographic representation of permafrost-free belts, which are bounded above and below by permafrost. This enables a high quality of permafrost modelling, as is shown by the validation of our map. The dominating influence of the two rather simple connected factors, elevation (as a proxy for mean annual air temperature) and solar radiation, on the distribution of ice-poor permafrost is significant for permafrost modelling in different climate conditions and regions. Indicating temperatures of ice-poor permafrost and distinguishing between ice-poor and ice-rich permafrost on a national permafrost map provides new information for users.

Thermal characteristics of tubular receivers of solar radiation line concentrators

2013 ◽  
Vol 49 (4) ◽  
pp. 235-240 ◽  
Author(s):  
Sh. I. Klychev ◽  
R. A. Zakhidov ◽  
R. Khuzhanov ◽  
Z. Sh. Klychev ◽  
F. Mukhtarov ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Thermal Characteristics ◽  
Radiation Line
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