CONJUGATE HEAT TRANSFER IN A TURBULENT CHANNEL FLOW WITH THROUGH SUBSTRATE COOLING FROM DISCRETE HEAT SOURCES

1994 ◽  
Author(s):  
S. Abhyankar ◽  
James A. Liburdy
Keyword(s):  
Heat Transfer ◽  
Channel Flow ◽  
Conjugate Heat Transfer ◽  
Turbulent Channel Flow ◽  
Heat Sources ◽  
Discrete Heat Sources

Effects of Protrusions on Conjugate Heat Transfer in a Microtube or Microchannel

2010 ◽  
Author(s):  
Muhammad M. Rahman ◽  
Phaninder Injeti
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Conjugate Heat Transfer ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Heat Sources ◽  
Two Dimensional ◽  
Discrete Heat Sources ◽  
Global Performance ◽  
Tube Geometry

Effects of protrusions on heat transfer in a microtube and in a two-dimensional microchannel of finite wall thickness were investigated for various shapes and sizes of the protrusion. Calculations were done for incompressible flow of a Newtonian fluid with developing momentum and thermal boundary layers under uniform and discrete heating conditions. It was found that the local Nusselt number near the protrusions changes significantly with the variations of Reynolds number, height, width, and distance between protrusions, and the distribution of discrete heat sources. The results presented in the paper demonstrate that protrusions can be used advantageously for the enhancement of local heat transfer whereas the global performance may be enhanced or diminished based on the tube geometry.

scholarly journals Predictions of Conjugate Heat Transfer in Turbulent Channel Flow using Advanced Wall-Modeled Large Eddy Simulation Techniques

Entropy ◽  
2021 ◽  
Vol 23 (6) ◽  
pp. 725
Author(s):  
Yongxiang Li ◽  
Florian Ries ◽  
Kaushal Nishad ◽  
Amsini Sadiki
Keyword(s):  
Heat Transfer ◽  
Large Eddy Simulation ◽  
Channel Flow ◽  
Entropy Generation ◽  
Transfer Process ◽  
Conjugate Heat Transfer ◽  
Turbulent Channel Flow ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Solid Region

In this paper, advanced wall-modeled large eddy simulation (LES) techniques are used to predict conjugate heat transfer processes in turbulent channel flow. Thereby, the thermal energy transfer process involves an interaction of conduction within a solid body and convection from the solid surface by fluid motion. The approaches comprise a two-layer RANS–LES approach (zonal LES), a hybrid RANS–LES representative, the so-called improved delayed detached eddy simulation method (IDDES) and a non-equilibrium wall function model (WFLES), respectively. The results obtained are evaluated in comparison with direct numerical simulation (DNS) data and wall-resolved LES including thermal cases of large Reynolds numbers where DNS data are not available in the literature. It turns out that zonal LES, IDDES and WFLES are able to predict heat and fluid flow statistics along with wall shear stresses and Nusselt numbers accurately and that are physically consistent. Furthermore, it is found that IDDES, WFLES and zonal LES exhibit significantly lower computational costs than wall-resolved LES. Since IDDES and especially zonal LES require considerable extra work to generate numerical grids, this study indicates in particular that WFLES offers a promising near-wall modeling strategy for LES of conjugated heat transfer problems. Finally, an entropy generation analysis using the various models showed that the viscous entropy production is zero inside the solid region, peaks at the solid–fluid interface and decreases rapidly with increasing wall distance within the fluid region. Except inside the solid region, where steep temperature gradients lead to high (thermal) entropy generation rates, a similar behavior is monitored for the entropy generation by heat transfer process.

Conjugate Heat Transfer From a Vertical Plate With Discrete Heat Sources Under Natural Convection

1989 ◽  
Vol 111 (4) ◽  
pp. 261-267 ◽  
Author(s):  
S. Lee ◽  
M. M. Yovanovich
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Conjugate Heat Transfer ◽  
Vertical Plate ◽  
Power Level ◽  
Radiation Heat Transfer ◽  
Transfer Model ◽  
Heat Sources ◽  
Radiation Heat ◽  
Discrete Heat Sources

A quasi-analytical conjugate heat transfer model is developed for a two dimensional vertical flat plate with discrete heat sources of arbitrary size and power level under natural convection. The plate is located in an extensive, quiescent fluid which is maintained at uniform temperature. The model consists of an approximate analytical boundary layer solution and a one dimensional numerical conduction analysis in which an allowance is made to account for radiation heat transfer. These fluid and solid solutions are coupled through an iterative procedure. A conjugate problem is solved when a converged temperature distribution is obtained at the plate-fluid interface, concurrently satisfying the thermal fields on both sides of the interface. Comparisons of the surface temperature variations obtained by using the present model are made with existing numerical and experimental data which were obtained for cases with two strip heat sources mounted flush with the surface of a vertical plate in air. The model is shown to be in good agreement. In addition, the convection and radiation heat flux variations are presented. The results illustrate the importance of radiation heat transfer for estimating surface temperatures of the plate.

A Numerical Simulation of Conjugate Heat Transfer in an Electronic Package Formed by Embedded Discrete Heat Sources in Contact With a Porous Heat Sink

1997 ◽  
Vol 119 (1) ◽  
pp. 8-16 ◽  
Author(s):  
A. G. Fedorov ◽  
R. Viskanta
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Conjugate Heat Transfer ◽  
Heat Transfer Analysis ◽  
Model Parameters ◽  
Heat Sources ◽  
Similar System ◽  
Electronic Package ◽  
Conjugate System ◽  
Discrete Heat Sources

A physical/mathematical model has been developed to simulate the conjugate heat transfer in an actively cooled electronic package. The package consists of a highly conductive substrate with embedded discrete heat sources that are in intimate contact with a porous channel through which a gaseous coolant is circulated. The flow in the porous medium is analyzed using the extended Darcy model. The nonequilibrium, two-equation model which accounts for the near wall thermal dispersion effects was used for the heat transfer analysis. The concept of the general energy equation for the entire physical domain was employed as a method of solving numerically the conjugate system. The model has been validated by comparing the predictions with available experimental data for a similar system. A parametric study has been performed to examine the effects of some of the most important model parameters on the thermal performance of porous heat sink.

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