Bayesian surrogates for integrating numerical, analytical and experimental data: application to inverse heat transfer in wearable computers

2002 ◽  
Author(s):  
N. Leoni ◽  
C. Amon
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Wearable Computers ◽  
Inverse Heat Transfer ◽  
Data Application

Effect of Spray Angle in Spray Cooling Thermal Management of Electronics

Volume 4 ◽  
2004 ◽  
Author(s):  
J. Schwarzkopf ◽  
T. Cader ◽  
K. Okamoto ◽  
B. Q. Li ◽  
B. Ramaprian
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Thermal Management ◽  
Numerical Study ◽  
Element Model ◽  
Spray Cooling ◽  
Spray Angle ◽  
Inverse Heat Transfer ◽  
Thermal Management Of Electronics ◽  
Swirl Atomizer

The paper presents an experimental and numerical study of the effect of spray angle on spray cooling when applied in the thermal management of electronics. A thermal test chip provided the heated target, and was cooled by a single pressure swirl atomizer. A perfluorocarbon (PF5060) was employed as the coolant. The coolant was subcooled to a fixed level of 26° C, and was sprayed directly onto the heated target at a fixed flow rate of 22 ml/min. The spray angle was varied between 0 and 60 degrees, and the outlet of the atomizer was located at a fixed radius of 1.4 cm from the heated target. The model of Mudawar and Estes (1996) was also modified to account for the effect of spray angle, then used to assist in interpretation of the experimental data. In an effort to estimate the heat transfer characteristics, an inverse heat transfer algorithm is developed. A direct finite element model is applied with estimated heat flux distributions to simulate the thermal field in the test microchip for various cooling conditions. Experimental results are presented for a number of cases and compared with the model’s predictions. The experimental data and model both showed that cooling capability dropped off when spray angle exceeded 50 degrees.

scholarly journals Experimental analysis and ANN prediction on performances of finned oval-tube heat exchanger under different air inlet angles with limited experimental data

Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 968-980
Author(s):  
Xueping Du ◽  
Zhijie Chen ◽  
Qi Meng ◽  
Yang Song
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Heat Exchanger ◽  
Correlation Equation ◽  
Tube Heat Exchanger ◽  
Flow Friction ◽  
Air Inlet ◽  
Comparison Results ◽  
Wide Range ◽  
Oval Tube

Abstract A high accuracy of experimental correlations on the heat transfer and flow friction is always expected to calculate the unknown cases according to the limited experimental data from a heat exchanger experiment. However, certain errors will occur during the data processing by the traditional methods to obtain the experimental correlations for the heat transfer and friction. A dimensionless experimental correlation equation including angles is proposed to make the correlation have a wide range of applicability. Then, the artificial neural networks (ANNs) are used to predict the heat transfer and flow friction performances of a finned oval-tube heat exchanger under four different air inlet angles with limited experimental data. The comparison results of ANN prediction with experimental correlations show that the errors from the ANN prediction are smaller than those from the classical correlations. The data of the four air inlet angles fitted separately have higher precisions than those fitted together. It is demonstrated that the ANN approach is more useful than experimental correlations to predict the heat transfer and flow resistance characteristics for unknown cases of heat exchangers. The results can provide theoretical support for the application of the ANN used in the finned oval-tube heat exchanger performance prediction.

Deteriorated turbulent heat transfer (DTHT) of gas up-flow in a circular tube: Experimental data

2008 ◽  
Vol 51 (13-14) ◽  
pp. 3259-3266 ◽  
Author(s):  
J.I. Lee ◽  
P. Hejzlar ◽  
P. Saha ◽  
P. Stahle ◽  
M.S. Kazimi ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Circular Tube ◽  
Turbulent Heat Transfer ◽  
Turbulent Heat

Oscillatory Heat Transfer in a Pipe Subjected to a Laminar Reciprocating Flow

1996 ◽  
Vol 118 (3) ◽  
pp. 592-597 ◽  
Author(s):  
T. S. Zhao ◽  
P. Cheng
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Heat Flux ◽  
Nusselt Number ◽  
Numerical Study ◽  
Temperature Cycle ◽  
Uniform Heat Flux ◽  
Fluid Temperature ◽  
Cycle Space ◽  
Reciprocating Flow

An experimental and numerical study has been carried out for laminar forced convection in a long pipe heated by uniform heat flux and subjected to a reciprocating flow of air. Transient fluid temperature variations in the two mixing chambers connected to both ends of the heated section were measured. These measurements were used as the thermal boundary conditions for the numerical simulation of the hydrodynamically and thermally developing reciprocating flow in the heated pipe. The coupled governing equations for time-dependent convective heat transfer in the fluid flow and conduction in the wall of the heated tube were solved numerically. The numerical results for time-resolved centerline fuid temperature, cycle-averaged wall temperature, and the space-cycle averaged Nusselt number are shown to be in good agreement with the experimental data. Based on the experimental data, a correlation equation is obtained for the cycle-space averaged Nusselt number in terms of appropriate dimensionless parameters for a laminar reciprocating flow of air in a long pipe with constant heat flux.

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