Heat Transfer Characteristics for a Confined Rotating MCM Disk With Round Jet Array Impingement

2007 ◽  
Author(s):  
C. Y. Lee ◽  
C. J. Fang ◽  
C. H. Peng ◽  
T. W. Lin ◽  
Y. H. Hung
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Steady State ◽  
Jet Impingement ◽  
Separation Distance ◽  
Heat Transfer Characteristics ◽  
Round Jet ◽  
Transfer Characteristics ◽  
Disk Rotation ◽  
Jet Array

An effective method of design of experiments combined with Central Composite Design for exploring the heat transfer characteristics for a confined rotating Multi-Chip Module (MCM) disk with round jet array impingement has been successfully developed. The relevant parameters influencing heat transfer performance include the steady-state Grashof number (Grs), ratio of jet separation distance to nozzle diameter (H/d), jet Reynolds number (Rej) and rotational Reynolds number (Rer). Their effects on heat transfer characteristics have been systematically explored. An axisymmetrical temperature distribution is ensured for various Grs, Rej, Rer and H/d ratios. As compared with the mutual effects of jet array impingement and disk rotation cause a more non-uniform distribution of chip temperatures. For heat transfer behavior, a new correlation of stagnation Nusselt number for jet array impingement at r/R = 0 in terms of Rej and H/d is presented. As compared with the experimental steady-state data of single round jet impingement, the average heat transfer enhancement at stagnation point r/R = 0 of jet array impingement is 607%. For the rotating MCM disk cases, the highest chip heat transfer occurs at the MCM disk rim, and decreases sharply along the distance from the surface edge toward the surface center.

Convective Heat Transfer From a Stationary or Rotating MCM Disk With a Unconfined Round Jet Impingement

2005 ◽  
Author(s):  
Y. M. Kuo ◽  
C. J. Fang ◽  
M. C. Wu ◽  
C. H. Peng ◽  
Y. H. Hung
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Steady State ◽  
Mixed Convection ◽  
Jet Impingement ◽  
Disk Surface ◽  
Separation Distance ◽  
Heat Flux Distribution ◽  
Disk Rotation ◽  
Nusselt Numbers

A series of experimental investigations with stringent measurement methods on the studies related to fluid flow and transient mixed convection from a horizontally unconfined stationary or rotating ceramic-based MCM disk with unconfined jet impingement have been successfully conducted. The relevant parameters influencing fluid flow and heat transfer performance are (1) mixed convection due to jet impingement and buoyancy: steady-state Grashof number, jet Reynolds number, and ratio of jet separation distance to nozzle diameter; and (2) mixed convection due to jet impingement, disk rotation and buoyancy: steady-state Grashof number, jet Reynolds number (Rej), rotational Reynolds number (Rer), ratio of jet separation distance to nozzle diameter (H/d). The thermal behavior explored includes the transient temperature distribution on the MCM disk surface, transient heat flux distribution of input power, transient convective heat flux distribution of chips, and transient chip and average heat transfer characteristics on the MCM disk surface. Besides, two new correlations of transient stagnation and average Nusselt numbers in terms of Rej, H/d and t are presented for the cases of stationary MCM disk. For the cases of rotating MCM disk, a new empirical correlation to classify two regimes of heat transfer modes such as disk rotation mode and jet impingement mode is presented; and a complete composite correlation of steady-state average Nusselt number for mixed convection due to jet impingement, disk rotation and buoyancy is proposed. As compared with the steady-state results, if the transient chip and average heat transfer behaviors may be considered as a superposition of a series of quasi-steady states, the transient chip and average Nusselt numbers in all the present transient experiments can be properly predicted by the existing steady-state correlations when t > 6 min in the power-on transient period.

Thermal Optimal Design for Multichip Module Disks With an Unconfined Round-Jet Impingement

2005 ◽  
Author(s):  
C. J. Fang ◽  
M. C. Wu ◽  
C. H. Peng ◽  
Y. C. Lee ◽  
Y. H. Hung
Keyword(s):  
Experimental Data ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Steady State ◽  
Thermal Performance ◽  
Jet Impingement ◽  
Separation Distance ◽  
Grashof Number ◽  
Round Jet ◽  
Space Limitation

An effective method for performing the thermal optimization of stationary and rotating MCM disks with an unconfined round-jet impingement under space limitation constraint has been successfully developed. The design variables of stationary and rotating MCM disks with an unconfined round-jet impingement include: the ratio of jet separation distance to nozzle diameter (H/d), steady-state Grashof number (Grs), jet Reynolds number (Rej), rotational Reynolds number (Rer). The total experimental cases for stationary and rotating MCM disks are statistically designed by the Central Composite Design (CCD) method. In addition, a sensitivity analysis, the so-called ANOVA, for the design factors has been performed. In the stationary MCM disk with an unconfined round-jet impingement, the contribution percentage of jet Reynolds number on the thermal performance is 95.86%. The effect of jet Reynolds numbers on chip temperature distribution is more significant than that of the H/d ratio and steady-state Grashof number. In rotating MCM disk with an unconfined round-jet impingement, the effect of jet Reynolds number, which has the contribution percentage of 91.81%, dominates the thermal performance. Furthermore, the comparisons between the predictions by using the quadratic Response Surface Methodology (RSM) and the experimental data are made. The maximum deviations for transient stagnation Nusselt number and transient average Nusselt number for the cases of stationary MCM disk are 10.05% and 11.82%, respectively; and 9.41% and 12.44% for the cases of rotating MCM disk, respectively. Finally, with the Sequential Quadratic Programming (SQP) technique, a series of thermal optimal designs under space limitation constraint H/d≤12 has been efficiently performed. Comparisons between the numerical optimization results and the experimental data are made with a satisfactory agreement.

Numerical Simulation Study of Impinging Jet Impact Fin Surface on Heat Transfer Characteristics

2013 ◽  
Vol 663 ◽  
pp. 586-591 ◽  
Author(s):  
Li Ming Zhou ◽  
Lei Zhu ◽  
Jing Quan Zhao ◽  
Meng Zheng
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Thermal Resistance ◽  
Jet Impingement ◽  
Impinging Jet ◽  
Heat Transfer Characteristics ◽  
Transfer Coefficients ◽  
Transfer Characteristics ◽  
Jet Impact ◽  
Jet Array

Three-dimensional numerical simulation was implemented to analyze the heat transfer characteristics for jet impingement impact fin surface. 60 calculation cases were simulated to investigate the effects of different fin surfaces on heat transfer characteristics, and 12 jet array impingement cases were calculated for comparison. The results shown that the fin shape, the height and the fin arrangement were the critical factors to affect the jet impingement and the best combination were existed in a certain range. The thermal resistance of cylinder fin arranged in order was34.7 percent higher than that of cylinder fin arranged staggered. The thermal resistance of square fin arranged in order was38.9 percent higher than that of square fin arranged staggered .The heat transfer coefficients of impinging jet impact fin surface were better than that of jet array impingement. The fitting correlations on heat transfer of impinging jet impact fin surface were given.

Numerical Study on Flow and Heat Transfer Characteristics of Jet Impingement Cooling

2011 ◽  
Vol 148-149 ◽  
pp. 680-683
Author(s):  
Run Peng Sun ◽  
Wei Bing Zhu ◽  
Hong Chen ◽  
Chang Jiang Chen
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Numerical Study ◽  
Cross Flow ◽  
Jet Impingement ◽  
Local Heat Transfer ◽  
Transfer Characteristic ◽  
Heat Transfer Characteristics ◽  
Impingement Cooling ◽  
Transfer Characteristics

Three-dimensional numerical study is conducted to investigate the heat transfer characteristics for the flow impingement cooling in the narrow passage based on cooling technology of turbine blade.The effects of the jet Reynolds number, impingement distance and initial cross-flow on heat transfer characteristic are investigated.Results show that when other parameters remain unchanged local heat transfer coefficient increases with increase of jet Reynolds number；overall heat transfer effect is reduced by initial cross-flow；there is an optimal distance to the best effect of heat transfer.

Heat-Transfer Optimization for Multichip Module Disks With an Unconfined Round Air Jet Impingement

2007 ◽  
Vol 129 (4) ◽  
pp. 411-420
Author(s):  
Y. C. Lee ◽  
C. J. Fang ◽  
M. C. Wu ◽  
C. H. Peng ◽  
Y. H. Hung
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Design Method ◽  
Jet Impingement ◽  
Separation Distance ◽  
Multichip Module ◽  
Programming Technique ◽  
Grashof Number ◽  
Round Jet ◽  
Air Jet

An effective method for performing the thermal optimization of stationary and rotating multichip module (MCM) disks with an unconfined round-jet impingement under space limitation constraint has been successfully developed. The design variables of stationary and rotating MCM disks with an unconfined round-jet impingement include the ratio of jet separation distance to nozzle diameter, Grashof number, jet Reynolds number, and rotational Reynolds number. The total experimental cases for stationary and rotating MCM disks are statistically designed by the central composite design method. In addition, a sensitivity analysis, the so-called analysis of variance, for the design factors has been performed. Among the influencing parameters, the jet Reynolds number dominates the thermal performance, while the Grashof number is found to have the least effect on heat-transfer performance for both stationary and rotating cases. Furthermore, the comparisons between the predictions by using the quadratic response surface methodology and the experimental data for both stationary and rotating cases are made with a satisfactory agreement. Finally, with the sequential quadratic programming technique, a series of thermal optimizations under multiconstraints—such as space, jet Reynolds number, rotational Reynolds number, nozzle exit velocity, disk rotational speed, and various power consumptions—has been systematically explored and discussed.

Heat Transfer Characteristics of CuO-Water Nanofluids Jet Impingement on a Hot Surface

2016 ◽  
Author(s):  
Sandesh S. Chougule ◽  
Mayank Modak ◽  
Prajakta D. Gharge ◽  
S. K. Sahu
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Jet Impingement ◽  
Target Surface ◽  
Test Surface ◽  
Initial Surface ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Impingement Heat Transfer ◽  
Hot Surface

In present study, an experimental investigation has been carried out to analyze the heat transfer characteristics of CuO-water nanofluids jets on a hot surface. A rectangular stainless steel foil (AISI-304, 0.15 mm thick) is used as a test surface is electrically heated to obtain the required initial temperature. The distribution of heat flux on the target surface is evaluated from the recorded thermal images during transient cooling. The effect of nanoparticle concentration and Reynolds number of the nanofluids jet impingement heat transfer characteristics is studied. Tests were performed for an initial surface temperature of 500°C, Reynolds number (5000≤Re≤13000), CuO-water nanofluids concentration (Φ= 0.15%, 0.6%) and nozzle to plate distance was l/d= 4.

An Experimental Investigation on Heat Transfer Characteristics of Hot Surface by Using CuO–Water Nanofluids in Circular Jet Impingement Cooling

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Mayank Modak ◽  
Sandesh S. Chougule ◽  
Santosh K. Sahu
Keyword(s):  
Heat Transfer ◽  
Experimental Investigation ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Jet Impingement ◽  
Test Surface ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Hot Surface ◽  
Plate Distance

In the present study, an experimental investigation has been carried out to analyze the heat transfer characteristics of CuO–water nanofluids jet on a hot surface. A rectangular stainless steel foil (AISI-304, 0.15 mm thick) used as the test surface is electrically heated to obtain the required initial temperature (500 °C). The distribution of surface heat flux on the target surface is evaluated from the recorded thermal images during transient cooling. The effect of nanoparticle concentration and Reynolds number of the nanofluids on the heat transfer characteristics is studied. Tests are performed for varied range of Reynolds number (5000 ≤ Re ≤ 12,000), two different CuO–water nanofluids concentration (Ф = 0.15%, 0.6%) and two different nozzle to plate distance (l/d = 6, 12). The enhancement in Nusselt number for CuO–water nanofluids was found to be 14% and 90%, for nanofluids concentration of Ф = 0.15% and Ф = 0.60%, respectively, compared to pure water. The test surface characteristics after nanofluids jet impingement are studied using scanning electron microscope (SEM). Based on the investigation, a correlation among various parameters, namely, Reynolds number (Re), Prandtl number (Pr), nozzle to plate distance (l/d), and Nusselt number (Nu), is presented.

Numerical Investigations of Flow and Heat Transfer Characteristics Between Turbulent Double Jet Impingement and a Moving Plate

2019 ◽  
Vol 11 (5) ◽  
Author(s):  
N. Satish ◽  
K. Venkatasubbaiah
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Jet Impingement ◽  
Heat Transfer Characteristics ◽  
Moving Plate ◽  
Enhancement Of Heat Transfer ◽  
Transfer Characteristics ◽  
Flow And Heat Transfer ◽  
Plate Velocity ◽  
Single Jet

The analysis of fluid flow and heat transfer characteristics of double turbulent jet flow impinging on a stationary and moving plate has been numerically studied. Unsteady-state two-dimensional incompressible turbulent forced convection flow is considered for present analysis. Turbulence is modelled by the Reynolds-averaged Navier–Stokes (RANS) equation with the k − ε model and enhanced wall treatment. The governing equations are solved using a finite volume based commercial solver. The results for the effect of single jet and double jet, jet Reynolds number, plate velocity, location, and center spacing between the two jets on flow and heat transfer characteristics are reported. The results show that the enhancement of heat transfer is 32.70% for the double jet compared with the single jet impingement on a stationary plate. As significant enhancement of heat transfer is observed with an increase in the second jet Reynolds number and plate velocity. The results show that the size and shape of the recirculation zones between jets are greatly altered with respect to spacing between the jets to the plate and the center distance between the jets. The results show that the enhancement of heat transfer is 37.3% for moving plate velocity due to a decrease in the spacing between the jets and the plate from 6 to 4. Results show that the local peak Nusselt number is influenced by the plate velocity. These results are validated by experimental and numerical results available in the literature.

Numerical Study on Flow and Heat Transfer Characteristics of Jet Impingement

2011 ◽  
Author(s):  
Xinjun Wang ◽  
Rui Liu ◽  
Xiaowei Bai ◽  
Jinling Yao
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Average Nusselt Number ◽  
Jet Impingement ◽  
Target Surface ◽  
Heat Transfer Characteristics ◽  
Impingement Cooling ◽  
Transfer Characteristics ◽  
Flow And Heat Transfer

A mathematical model used for studying jet impingement cooling characteristics is established, and the rationality of the calculation model and method is confirmed by the experimental data. The CFX software is used to numerically simulate the jet impingement cooling characteristics on a gas turbine blade. The effects of various parameters, such as the arrays of impinging nozzles, the jet Reynolds number, the jet-to-jet distance, the ratio of nozzle-to-surface spacing to jet diameter H/d, and the radius of curvature of the target surface, on the flow and heat transfer characteristics of a impingement cooling process are studied. The results indicate that the impingement jets can make complex vortex in the cooling channel, the flow boundary layer is extremely thin and highly turbulent. Underneath each impingement nozzle, there will appear a low temperature area and a peak of Nusselt number on the impingement target surface, the distribution of temperature and Nusselt number on the target surface are associated with arrangement of impingement nozzles. The average Nusselt number of the in-line arrangement nozzles is higher than that of the staggered arrangement ones. With the increasing of jet Reynolds number, the velocity impinging on the target surface and Nusselt number increase. However, heat transfer of impingement cooling on target surface is not sensitive to the jet nozzles distance; the velocity impinging on the target surface and Nusselt number decrease with the increasing of the H/d value. For the curved target surface cases, the average Nusselt number of the target surface and the effect of heat transfer decreased with the increasing of curvature radius R.

Effect of Jet Position on Cooling an Array of Heated Obstacles

2017 ◽  
Vol 10 (1) ◽  
Author(s):  
Hussein M. Maghrabie ◽  
M. Attalla ◽  
H. E. Fawaz ◽  
M. Khalil
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Flow Structure ◽  
Numerical Study ◽  
Cross Flow ◽  
Jet Impingement ◽  
Pumping Power ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Number Ratio

Numerical study of the effect of jet position (JP) on cooling process of an array of heated obstacles simulating electronic components has been investigated based on realizable k–ε model. Jet positions have been changed to impinge each row of obstacles consecutively. The experiments have been achieved at three different values of jet-to-channel Reynolds number ratio, Rej/Rec = 1, 2, and 4. In this study, a comparison between two different cooling processes, cross flow only (CF) and jet impingement with cross flow (JICF), has been achieved. The flow structure, heat transfer characteristics, and the pumping power have been investigated for different jet positions. The results show that the jet position affects significantly the flow structure, as well as the heat transfer characteristics. According to the results of average heat transfer coefficient and the pumping power, the more effective jet position for all values of jet-to-channel Reynolds number ratio (1, 2, and 4) is achieved when the jets impinge the third row of obstacles (JP3).

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