Boundary Condition Independent Thermal Model

2005 ◽  
pp. 345-348
Author(s):  
Evgenii B. Rudnyi ◽  
Jan G. Korvink
Keyword(s):  
Boundary Condition ◽  
Thermal Model

Development of Delphi-Type Compact Thermal Models for Opto-Electronic Packages

2011 ◽  
Vol 133 (1) ◽  
Author(s):  
Arun Prakash Raghupathy ◽  
John Janssen ◽  
Attila Aranyosi ◽  
Urmila Ghia ◽  
Karman Ghia ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Boundary Condition ◽  
Thermal Model ◽  
Integrated Design ◽  
Physical Models ◽  
Junction Temperature ◽  
Small Subset ◽  
Electronic Packages ◽  
Detailed Model ◽  
Small Form Factor

In the current study, a network-based resistor model has been developed for thermal analysis of a complex opto-electronic package called small form-factor pluggable device (SFP). This is done using the DEvelopment of Libraries of PHysical models for an Integrated design (DELPHI) methodology. The SFP is an optical transceiver widely used in telecommunication equipments such as switches and routers. The package has a detailed construction and typically has four fixed heat generating sources. The detailed model for the SFP is constructed and calibrated using a natural convection experiment. The calibrated detailed model is used for generating the limited boundary-condition-independent compact thermal model (CTM). Limited boundary-condition-independence, in this case, refers only to a small subset of all “thinkable” boundary conditions that are experienced by the SFP device in practical situations. The commercial optimization tool developed by the DELPHI team, DOTCOMP, is used for generating the compact thermal model. A detailed validation of the CTM of the SFP in real-time applications using FLOTHERM 7.2, a computational fluid dynamics-based thermal analysis software package, is performed. The results show excellent agreement between the results predicted by the SFP CTM with the data from the detailed model. The SFP CTM predicts the junction temperature of the four power-dissipating components and the heat flows through the sides with relative error less than 10%.

Detailing an Improved Heat Transfer Model for Pavements

2021 ◽  
pp. 036119812199484
Author(s):  
James Bryce ◽  
Arka Chattopadhyay ◽  
Mehdi Esmaeilpour ◽  
Zack E. Ihnat
Keyword(s):  
Climate Change ◽  
Heat Transfer ◽  
Boundary Condition ◽  
Thermal Model ◽  
Urban Heat Islands ◽  
Transfer Model ◽  
Lower Boundary Condition ◽  
Heat Islands ◽  
Analysis And Design ◽  
Urban Heat

Temperature profiles are a fundamental input into mechanistic-empirical pavement analysis and design, and the enhanced integrated climatic model (EICM) is the state-of-the-practice for calculating those profiles. The EICM has also been used in other applications, such as analysis to evaluate the effects of climate change on pavements and to estimate the effects of pavements on urban heat islands. The calculations in the EICM for pavement temperatures can be viewed as having two primary components that together act as a system: the thermal model describing conductance of temperatures throughout the pavement, and the boundary conditions that include the convective terms at the pavement surface, an energy balance model to predict the solar radiation at the surface of the pavement and a specified lower boundary condition (generally constant temperature at defined depth). As is shown in this paper, the current EICM models overpredict temperatures during hot times and in no-wind conditions, while also underpredicting (albeit to a lesser magnitude) during cold conditions. This result implies that the increases in pavement temperatures predicted to occur with climate change are likewise overestimated. Conversely, because the convection coefficient is incorrect, the predicted amount of energy contributing to urban heat islands will also not be correctly predicted using the current EICM models. Although improvements to the solar model are noted, this paper focuses on improvements to the thermal model and convective boundary condition using modern heat transfer principles and data from the Long-Term Pavement Performance database.

A New Method to Determine the Upper Boundary Condition for a Permafrost Thermal Model: An Example from the Qinghai-Tibet Plateau

2012 ◽  
Vol 23 (4) ◽  
pp. 301-311 ◽  
Author(s):  
Mingyi Zhang ◽  
Ki-Hong Min ◽  
Qingbai Wu ◽  
Jianming Zhang ◽  
Jon Harbor
Keyword(s):  
Boundary Condition ◽  
Thermal Model ◽  
New Method ◽  
Tibet Plateau ◽  
Qinghai Tibet Plateau ◽  
Upper Boundary

Effect of Temperature Gradient on End Cell Water Transport in a Polymer Electrolyte Fuel Cell After Shutdown

2009 ◽  
Author(s):  
Manish Khandelwal ◽  
Matthew M. Mench
Keyword(s):  
Boundary Condition ◽  
Fuel Cell ◽  
Temperature Gradient ◽  
Single Cell ◽  
Water Transport ◽  
Thermal Model ◽  
Cell Model ◽  
Single Cell Level ◽  
Cell Water ◽  
Cell Level

In a PEFC stack, end cells are subjected to severe conditions compared to the center cell, sometimes resulting in poor end cell performance and early freeze out. In this work, the concept of using controlled temperature gradients to non-parasitically remove excess water from end cell during PEFC stack shutdown has been numerically investigated. To investigate the end cell water transport, an integrated modeling approach focusing both at stack and single cell level is presented. The stack thermal model is developed to obtain detailed temperature distribution across the PEFC stack. Extending the results of the stack thermal model into a single cell level, a two-phase unit fuel cell model is developed to investigate the water and thermal transport in the PEFC components after shutdown, which for the first time includes thermo-osmotic flow in the membrane. The model accounts for capillary and phase-change induced flow in the porous media, and thermo-osmotic and diffusive flow in the polymer membrane. The single cell model is used to estimate the local water distribution with land/channel boundary condition, and the experimentally validated stack thermal model provided the transient temperature boundary condition to simulate the end cells. Model results indicate that a favorable temperature gradient can be formed in the stack to enhance the water drainage rate, thus enhancing the anode end cell cold start performance.

One-Dimensional Fin-Tip Boundary Condition Correction II

2001 ◽  
Vol 22 (5) ◽  
pp. 35-40 ◽  
Author(s):  
D. C. Look Jr ◽  
Arvind Krishnan
Keyword(s):  
Boundary Condition ◽  
One Dimensional

THERMAL MODEL FOR THE DESORPTION OF (MOLECULAR) IONS INDUCED BY MeV HEAVY IONS

1989 ◽  
Vol 50 (C2) ◽  
pp. C2-237-C2-243 ◽  
Author(s):  
H. VOIT ◽  
E. NIESCHLER ◽  
B. NEES ◽  
R. SCHMIDT ◽  
CH. SCHOPPMANN ◽  
...  
Keyword(s):  
Heavy Ions ◽  
Thermal Model ◽  
Molecular Ions
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