Experimental Investigation of the Heat Transfer Performance of Arrays of Round Jets With Sharp-Edged Orifices and Peripheral Effluent: Convective Behavior of Water on a Heated Silicon Surface

2005 ◽  
Author(s):  
Levi A. Campbell ◽  
Michael J. Ellsworth ◽  
Madhusudan Iyengar ◽  
Robert Simons ◽  
Richard Chu
Keyword(s):  
Heat Transfer ◽  
Data Reduction ◽  
Silicon Surface ◽  
Heated Surface ◽  
Orifice Diameter ◽  
Plate Height ◽  
Round Jets ◽  
Heated Area ◽  
Data Reduction Technique ◽  
Effective Heat Transfer Coefficient

In the present work, deionized water is impinged onto a heated silicon surface using square arrays of round jets. Various numbers of jets and jet diameters are used over a heated area of constant size with the orifice plate height above the heater held constant. In these experiments, the jet orifices are sharp-edged and the fluid exhaust direction is parallel to the heated surface and leaves the chip periphery through a manifold. The resulting temperature and flow data are presented in physical units as well as in groups of dimensionless parameters. A correlation is presented to reasonably predict the experimental results of this study. The techniques used for data reduction and for experimentation, including the construction of the test module, are given in detail, including a numerical conduction simulation based data reduction technique and uncertainty analysis. The results shown include flow rates ranging from 6.1 cc/s to 63.18 cc/s resulting in Reynolds numbers based on orifice diameter ranging from 141 to 6670. Jet diameters investigated in this study range from 377 μm to 1.01 mm, in square arrays of 16 to 324 orifices on an area of 18.52 mm × 18.59 mm. The resulting maximum spatially averaged effective heat transfer coefficient achieved is 7.94 W/cm2K, and the maximum spatially averaged Nusselt number based on jet diameter is 79.4.

Infrared Thermography Data Reduction Technique for Heat Transfer Measurements in the Boeing/AFOSR Mach-6 Quiet Tunnel

2019 ◽  
Author(s):  
Mirko Zaccara ◽  
Salvatore Cerasuolo ◽  
Gennaro Cardone ◽  
Joshua B. Edelman ◽  
Steven P. Schneider
Keyword(s):  
Heat Transfer ◽  
Infrared Thermography ◽  
Data Reduction ◽  
Reduction Technique ◽  
Data Reduction Technique

Fluid Motion and Heat Transfer of Boiling With Impinging Flow in a Mini-Tube With Nonlinear Thermocapillary Solutions

2010 ◽  
Author(s):  
Naoki Ono ◽  
Atsushi Hamaoka ◽  
Yuta Otsubo
Keyword(s):  
Heat Transfer ◽  
Aqueous Solution ◽  
Surface Tension ◽  
Heat Flux ◽  
Liquid Layer ◽  
Heated Surface ◽  
Pure Water ◽  
Heated Area ◽  
Impinging Flow ◽  
Butanol Solution

Boiling heat transfer with impinging flow can be an effective way for cooling a small heated area such as CPUs and laser emitting devices. In the phenomena the movement of liquid layer on the heated surface strongly affects the detachment of boiling bubbles and the heat flux. In this study, nonlinear thermocapillary solutions such as button aqueous solutions were applied to this type of boiling with impinging flow aiming to promote heat transfer. These solutions have special characteristics that the surface tension increases as the temperature is raised over some temperature. It is expected that this tendency about the surface tension will promote the wetting of the heated surface and the detachment of boiling bubbles. In the experiment, T-shaped mini tubes were built with quartz tubes and used for flow boiling. The inner diameter of the tube was 2 mm and the outer diameter was 4 mm. The liquid flow impinged at the junction point where small area was heated by using a conducting thin film coated at the outer surface of the tube. The test fluids were butanol aqueous solution and pure water. The flow rate of the liquid was the order of 1 ml/min, the concentration of the butanol aqueous solution was 7.15 wt %. The liquid motion was observed by CCD video camera system. It was found from the experiment that the motion of the liquid layer of the butanol solution at the impinging area was very different from that of pure water. The layer of the butanol solution tended to extend to the hotter part of the heated area. In another experiment for precisely fixing the imposed heat flux value, T-shaped mini channel with small copper surface installed for heating the fluid was prepared. The cross section of the channel was rectangular shape of 3 mm × 3 mm, and the entire channel was made of insulating polymer material. It was found that the heat transfer of the boiling with impinging flow in using butanol solution was more promoted than that in using pure water.

Experimental Investigation of Single-Phase Heat Transfer in a Plate Heat Exchanger

2015 ◽  
Vol 7 (4) ◽  
Author(s):  
Tariq S. Khan ◽  
Mohammad S. Khan ◽  
Zahid H. Ayub
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Data Reduction ◽  
Current Data ◽  
Plate Heat Exchanger ◽  
Plate Heat ◽  
Experimental Heat ◽  
Experimental Heat Transfer ◽  
Wilson Plot ◽  
Data Reduction Technique

The present experimental study is carried out to verify previously published heat transfer results attained using a simpler yet nascent data reduction technique for the same plate heat exchanger. A gasketed, commercially available plate heat exchanger with mixed (30/60) plate configuration was used in this study to obtain experimental heat transfer coefficient using modified Wilson plot method for data reduction. The comparison between current data and previously published results has shown excellent agreement between the two techniques hence verifying the results of the simpler method used earlier.

Mist/Steam Cooling by a Row of Impinging Jets

2001 ◽  
Author(s):  
X. Li ◽  
J. L. Gaddis ◽  
T. Wang
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Cfd Simulation ◽  
Heated Surface ◽  
Impinging Jets ◽  
Stagnation Line ◽  
Round Jets ◽  
Steam Cooling ◽  
The Heat Transfer Coefficient

Closed loop steam has been chosen for cooling airfoils in heavy frame Advanced Turbine Systems (ATS) to improve efficiency. Enhanced cooling by the use of mist is considered to have potential to augment cooling by internal steam alone. Water droplets generally less than 10μm are added to 1.3 bar steam and injected through a row of four discrete round jets onto a heated surface. The Reynolds number is varied from 7500 to 22500 and the heat flux varied from 3.3 to 13.4 kW/m2. The mist increases the heat transfer coefficient along the stagnation line and downstream wanes in about 5 jet diameters. The heat transfer coefficient improves by 50 to 700 percent at the stagnation line for mist concentrations 0.75 to 3.5 percent by weight, depending on conditions. Off-axis maximum cooling occurs in most of the mist/steam flow but not in the steam-only flow. CFD simulation indicates that this off-axis cooling peak is caused by droplets’ interaction with the target walls.

New Data Reduction Equation for Diamond Slug Calorimeter Heat Transfer Gauges

2020 ◽  
Vol 34 (4) ◽  
pp. 860-864
Author(s):  
J. I. Frankel ◽  
Rowland T. Penty Geraets ◽  
M. McGilvray ◽  
Hongchu Chen
Keyword(s):  
Heat Transfer ◽  
Data Reduction ◽  
Reduction Equation
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