scholarly journals Forced Convection from Heat Source on A Conductive Plate in an Air Rectangular Channel.(Dept.M)

2021 ◽  
Vol 24 (2) ◽  
pp. 56-67
Author(s):  
F. Araid
Keyword(s):  
Heat Source ◽  
Forced Convection ◽  
Rectangular Channel ◽  
Conductive Plate

An Experimental Study on Forced Convection Heat Transfer From Flush-Mounted Discrete Heat Sources

1999 ◽  
Vol 121 (2) ◽  
pp. 326-332 ◽  
Author(s):  
C. P. Tso ◽  
G. P. Xu ◽  
K. W. Tou
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Heat Source ◽  
Forced Convection ◽  
Rectangular Channel ◽  
Convection Heat Transfer ◽  
Channel Height ◽  
Air Cooling ◽  
Convection Heat ◽  
Forced Convection Heat Transfer

Experiments have been performed using water to determine the single-phase forced convection heat transfer from in-line four simulated electronic chips, which are flush-mounted to one wall of a vertical rectangular channel. The effects of the most influential geometric parameters on heat transfer including chip number, and channel height are tested. The channel height is varied over values of 0.5, 0.7, and 1.0 times the heat source length. The heat flux is set at the three values of 5 W/cm2, 10 W/cm2, and 20 W/cm2, and the Reynolds number based on the heat source length ranges from 6 × 102 to 8 × 104. Transition Reynolds numbers are deduced from the heat transfer data. The experimental results indicate that the heat transfer coefficient is affected strongly by the number of chips and the Reynolds number and weakly by the channel height. Finally, the present results from liquid-cooling are compared with other results from air-cooling, and Prandtl number scaling between air and water is investigated.

Single- and Two-Phase Convective Heat Transfer From Smooth and Enhanced Microelectronic Heat Sources in a Rectangular Channel

1989 ◽  
Vol 111 (4) ◽  
pp. 1045-1052 ◽  
Author(s):  
D. E. Maddox ◽  
I. Mudawar
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Heat Source ◽  
Convective Heat Transfer ◽  
Forced Convection ◽  
Convective Heat ◽  
Single Phase ◽  
Rectangular Channel ◽  
Heat Sources ◽  
Two Phase

Experiments have been performed to assess the feasibility of cooling microelectronic components by means of single-phase and two-phase forced convection. Tests were conducted using a single heat source flush mounted to one wall of a vertical rectangular channel. An inert fluorocarbon liquid (FC-72) was circulated upward through the channel at velocities up to 4.1 m/s and with subcooling up to 46°C. The simulated microelectronic heat sources tested in this study include a smooth surface and three low-profile microstud surfaces of varying stud height, each having a base area of 12.7×12.7 mm2. Correlations were developed for the single-phase convective heat transfer coefficient over the Reynolds number range from 2800 to 1.5 × 105, where Reynolds number is based on the length of the heater. The results demonstrate that the low thermal resistances required for cooling of microelectronic heat sources may be achieved with single-phase forced convection by using high fluid velocity coupled with surface enhancement. Experiments were also performed to understand better the parametric trends of boiling heat transfer from the simulated microelectronic heat source. It was found that increased velocity and subcooling and the use of microstud surfaces enhance nucleate boiling, increase the critical heat flux, and reduce the magnitude of temperature overshoot upon the inception of nucleation.

On Combined Free and Forced Convection in Channels

1960 ◽  
Vol 82 (3) ◽  
pp. 233-238 ◽  
Author(s):  
L. N. Tao
Keyword(s):  
Forced Convection ◽  
Rectangular Channel ◽  
Complex Function ◽  
Vertical Channel ◽  
Temperature Fields ◽  
Parallel Plates ◽  
Free And Forced Convection ◽  
Energy Equations ◽  
Helmholtz Wave Equation ◽  
Transfer Problems

The heat-transfer problems of combined free and forced convection by a fully developed laminar flow in a vertical channel of constant axial wall temperature gradient with or without heat generations are approached by a new method. By introducing a complex function which is directly related to the velocity and temperature fields, the coupled momentum and energy equations are readily combinable to a Helmholtz wave equation in the complex domain. This greatly reduces the complexities of the problems. For illustrations, the cases of flows between parallel plates and in a rectangular channel are treated. It shows that this method is more direct and powerful than those of previous investigations.

Visualization of Supercritical Carbondioxide Pseudo-Boiling Inside a Rectangular Channel

2001 ◽  
Author(s):  
K. Sakurai ◽  
H. S. Ko ◽  
K. Okamoto ◽  
H. Madarame
Keyword(s):  
Forced Convection ◽  
Supercritical Fluids ◽  
Nuclear Power ◽  
Power Reactor ◽  
Rectangular Channel ◽  
Visual Observation ◽  
Next Generation ◽  
Nuclear Power Reactor

Abstract The characteristics of the supercritical fluids should be precisely investigated for the next generation nuclear power reactor, i.e., Super-critical water Cooled Reactor (SCR). There are few experiments for visual observation especially in forced convection, because of the difficulty of the experiment.

Design Parameters and Practical Considerations in the Two-Phase Forced-Convection Cooling of Multi-Chip Modules

1992 ◽  
Vol 114 (3) ◽  
pp. 280-289 ◽  
Author(s):  
Christopher O. Gersey ◽  
Thomas C. Willingham ◽  
Issam Mudawar
Keyword(s):  
Forced Convection ◽  
Flow Rate ◽  
Rectangular Channel ◽  
Nucleate Boiling ◽  
Design Parameters ◽  
Two Phase ◽  
Chip Surface ◽  
Flow Area ◽  
Convection Cooling ◽  
Two Phase Cooling

Forced-convection boiling was investigated with a dielectric coolant (FC-72) in order to address some of the practical issues related to the two-phase cooling of multi-chip modules. The module used in the present study featured a linear array of nine, 10 × 10 mm2, simulated microelectronic chips which were flush-mounted along a 20-mm wide side of a rectangular channel. Experiments were performed with a 5-mm channel gap (distance between the chip surface and the opposing channel wall) at eight orientations spaced 45 degrees apart. Two other channel gaps, 2 and 10 mm, were tested in the vertical up flow configuration. For all these configurations, the velocity and subcooling of the liquid were varied from 13 to 400 cm/s and 3 to 36°C, respectively. Changes in orientation did not affect single-phase or nucleate boiling characteristics, but did have a major impact on CHF. Upflow conditions were found to be the best configuration for the design of two-phase cooling modules because of its inherently stable flow and relatively high CHF values. The CHF value for the most upstream chip in vertical upflow agreed well with a previous correlation for an isolated chip. Combined with the relatively small spread in CHF values for all chips in the array, this correlation was found to be attractive for design purposes in predicting CHF for a multi-chip array. To achieve a given CHF value, it is shown how the strong CHF dependence on velocity rather than flow area allows for a reduction in the required flow rate with the 2-mm, as compared to the 5-mm gap, which also required a smaller flow rate than the 10-mm gap. This reduction inflow rate was significant only with subcooled conditions corresponding to high CHF values.

Application of Different Conductive Substrate Materials for Heat Transfer Enhancement in Cooling of Electronic Components

2014 ◽  
Vol 1082 ◽  
pp. 327-331
Author(s):  
Thiago Antonini Alves ◽  
Murilo A. Barbur ◽  
Felipe Baptista Nishida
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Heat Transfer Enhancement ◽  
Forced Convection ◽  
Pure Aluminum ◽  
Rectangular Channel ◽  
Electronic Components ◽  
Transfer Enhancement ◽  
Cooling Process ◽  
Conductive Substrate

In this research, a study of the heat transfer enhancement in electronic components mounted in channels was conducted by using different materials in the conductive substrate. In this context, a numerical analysis was performed to investigate the cooling of 3D protruding heaters mounted on the bottom wall (substrate) of a horizontal rectangular channel using the ANSYS/FluentTM 15.0 software. Three different materials of the conductive substrate were analyzed, polymethyl methacrylate (PMMA), fiberglass reinforced epoxy laminate (FR4), and pure aluminum (Al). Uniform heat generation rate was considered for the protruding heaters and the cooling process happened through a steady laminar airflow, with constant properties. The fluid flow velocity and temperature profiles were uniform at the channel entrance. For the adiabatic substrate, the cooling process occurred exclusively by forced convection. For the conductive substrate, the cooling process was characterized by conjugate forced convection-conduction heat transfer through two mechanisms; one directly between the heaters surfaces and the flow by forced convection, and the other through conduction at the interfaces heater-substrate in addition to forced convection from the substrate to the fluid flow at the substrate surface. The governing equations and boundary conditions were numerically solved through a coupled procedure using the Control Volumes Method in a single domain comprising the solid and fluid regions. Commonly used properties in cooling of electronics components mounted in a PCB and typical geometry dimensions were utilized in the results acquisition. Some examples were presented, indicating the dependence of the substrate thermal conductivity related to the Reynolds number on the heat transfer enhancement. Thus, resulting in a lower work temperature at the electronic components.

Forced Convection in a Porous Channel With Localized Heat Sources

1994 ◽  
Vol 116 (2) ◽  
pp. 465-472 ◽  
Author(s):  
A. Hadim
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Pressure Drop ◽  
Heat Source ◽  
Forced Convection ◽  
Numerical Study ◽  
Porous Channel ◽  
Heat Sources ◽  
Porous Layers ◽  
Channel Configuration

A numerical study is performed to analyze steady laminar forced convection in a channel filled with a fluid-saturated porous medium and containing discrete heat sources on the bottom wall. Hydrodynamic and heat transfer results are reported for two configurations: (1) a fully porous channel, and (2) a partially porous channel, which contains porous layers above the heat sources and is nonporous elsewhere. The flow in the porous medium is modeled using the Brinkman-Forchheimer extended Darcy model. Heat transfer rates and pressure drop are evaluated for wide ranges of Darcy and Reynolds numbers. Detailed results of the evolution of the hydrodynamic and thermal boundary layers are also provided. The results indicate that as the Darcy number decreases, a significant increase in heat transfer is obtained, especially at the leading edge of each heat source. For fixed Reynolds number, the length-averaged Nusselt number reaches an asymptotic value in the Darcian regime. In the partially porous channel, it is found that when the width of the heat source and the spacing between the porous layers are of the same magnitude as the channel height, the heat transfer enhancement is almost the same as in the fully porous channel while the pressure drop is significantly lower. These results suggest that the partially porous channel configuration is a potentially attractive heat transfer augmentation technique for electronic equipment cooling, an end that motivated this study.

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