Heat Partition and Transient Temperature Distribution in Layered Concentrated Contacts. Part I—Theoretical Model

1987 ◽  
Vol 109 (3) ◽  
pp. 487-495 ◽  
Author(s):  
M. Rashid ◽  
A. Seireg
Keyword(s):  
Theoretical Model ◽  
Temperature Distribution ◽  
Heat Generation ◽  
Transient Temperature ◽  
Alternating Direction Implicit Method ◽  
Alternating Direction Implicit ◽  
Transient Temperature Distribution ◽  
Heat Partition ◽  
Alternating Direction ◽  
Computer Based

The study reported in this paper deals with the development of a generalized and efficient computer-based model for parametric evaluation of heat partition and transient temperatures in dry and lubricated layered concentrated contacts. The program utilizes finite differences with the alternating direction implicit method. It is capable of treating this general class of problems provided that the heat generation distribution and the layer properties and thicknesses are known.

Heat Partition and Transient Temperature Distribution in Layered Concentrated Contacts. Part II—Dimensionless Relationships and Numerical Results

1987 ◽  
Vol 109 (3) ◽  
pp. 496-501 ◽  
Author(s):  
M. Rashid ◽  
A. Seireg
Keyword(s):  
Temperature Distribution ◽  
Temperature Rise ◽  
Surface Coating ◽  
Numerical Results ◽  
Operating Conditions ◽  
Transient Temperature ◽  
Transient Temperature Distribution ◽  
Heat Partition ◽  
Recent Interest ◽  
Computer Based

The computer-based model described in Part I is utilized in this paper to develop dimensionless relationships for lubricated unlayered contacts and dry layered contacts. Because of the recent interest in tribological surface coating these relationships can be used to provide parametric evaluations of heat partition and temperature rise in the contacts under different coating parameters and operating conditions.

scholarly journals Post Fire Transient Temperature Distribution in Drum Type Packages

2006 ◽  
Author(s):  
Allen C. Smith
Keyword(s):  
Temperature Distribution ◽  
Thermal Resistance ◽  
Heat Generation ◽  
Thermal Response ◽  
Internal Resistance ◽  
Peak Temperature ◽  
Transient Temperature ◽  
Containment Vessel ◽  
Transient Temperature Distribution ◽  
Parametric Studies

This study investigates the temperature distribution in an idealized cylindrical package subjected to the HAC Fire transient. Cases for several common overpack materials, with thermal conductivity spanning two orders of magnitude, are considered. The results show that the interior temperature distribution and maximum interior temperature are determined by the heat generation of the contents and the thermal resistance of the package materials. Heat generation has a dominant effect on the peak temperature in the center (containment vessel region) of the package, when the internal thermal resistance is high. For cases where the internal resistance is low, heat conducted into the interior during the fire determines the peak temperature in the center, containment vessel region. The thermal wave effect, where the interior temperature continues to rise after the end of the fire exposure, is present in all cases. The study complements the parametric studies of effects of thermal properties on thermal response of packages which were previously reported.

Post Fire Transient Temperature Distribution in Drum Type Packages in the Absence of Heat Generation

2003 ◽  
Author(s):  
Allen C. Smith
Keyword(s):  
Thermal Conductivity ◽  
Temperature Distribution ◽  
Heat Generation ◽  
Heat Storage ◽  
Internal Heat ◽  
Thermal Response ◽  
Transient Temperature ◽  
Test Cases ◽  
Transient Temperature Distribution ◽  
Parametric Studies

This study investigates the temperature distribution in an idealized cylindrical package subjected to the HAC Fire transient, with no internal heat generation. Cases for overpack materials with thermal conductivity spanning two orders of magnitude are considered. The results show that the peak internal temperature is determined by the thermal conductivity of the overpack material, for this case. The thermal wave effect, where the interior temperature continues to rise after the end of the fire exposure, is present in all three of the test cases. For contents with no heat generation, the most desirable overpack materials would have low thermal conductivity and low heat storage capability. The study complements the parametric studies of effects of thermal properties on thermal response of packages which were previously reported.

scholarly journals Transient temperature distribution on the corneal endothelium during ophthalmic phacoemulsification: a numerical simulation using the nodeless variable element

2010 ◽  
Vol 4 (6) ◽  
pp. 885-892 ◽  
Author(s):  
Wiroj Limtrakarn ◽  
Somporn Reepolmaha ◽  
Pramote Dechaumphai
Keyword(s):  
Numerical Simulation ◽  
Temperature Distribution ◽  
Anterior Chamber ◽  
Heat Generation ◽  
Corneal Endothelium ◽  
Temperature Response ◽  
Maximum Temperature ◽  
Transient Temperature ◽  
Cataract Operation ◽  
Transient Temperature Distribution

Abstract Background: During cataract operation (phacoemulsification), a phaco needle-tip is inserted into the anterior chamber of eye. Then, heat is generated by the oscillation of the phaco needle, which may injury the corneal endothelial cells. There are no data available for temperature responses at the corneal endothelium to heat from the phaco needle during phacoemulsification. Objective: Investigate temperature distribution on the corneal endothelium during ophthalmic phacoemulsification using numerical simulation, and compare the transient temperature response to heat between balanced salt solution (BSS) and ophthalmic viscoelastic device (OVD), Viscoat®. Methods: Heat flux from a phaco needle was measured with thermal properties of BSS and AVS in an experimental setting. Then, nodeless variable finite element method was applied to predict temperature changes in the eye by the phaco needle inserted into the anterior chamber. The transient temperature distribution on the corneal endothelium was calculated at 10, 20, and 30 seconds after heat generation by the needle. Results: The heat generation of phaco needle without sleeve cover was 1.6 kW/m2. The numerical simulation showed that the maximum temperature occurs on the wound location at all times after heat generation by the phaco needle. Especially, at time 30 seconds, it was 49.2 and 41.7°C in BSS and OVD, respectively. The temperature elevation by the phaco needle was lower in OVD than BSS. Conclusion: Phacoemulsification is a heat-generating procedure performed between the anterior chamber structures of eye. During this procedure, OVD may protect the corneal endothelium against heat better than BSS.

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