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

Application of the Transient Test Technique to Measure Local Heat Transfer Coefficients Associated With Augmented Airfoil Cooling Passages

1987 ◽  
Author(s):  
H. J. Saabas ◽  
S. C. Arora ◽  
W. Abdel Messeh
Keyword(s):  
Heat Transfer ◽  
Data Reduction ◽  
Order Approximation ◽  
Bulk Temperature ◽  
Image Analysis System ◽  
Reduction Procedure ◽  
Test Technique ◽  
True Value ◽  
Time Space ◽  
Made In

The failure of a turbine airfoil is a local phenomena. However, to date, the design of these airfoils has been based on steady state heat transfer tests that are capable of yielding only locally averaged data. To overcome this limitation, a transient technique using active surface coatings has been developed and is capable of yielding local data. This technique has been used to determine the Nusselt number distributions within augmented passages typical of gas turbine airfoils. However, certain assumptions have been made in these analyses without verification. This paper will address this aspect of the problem, as well as an improved data reduction procedure, and an alternative error analysis. The data reduction procedure has been improved by incorporating a higher order approximation to the convective boundary condition, and by introducing a means of calculating the fluid bulk temperature-time-space profile. An image analysis system which yields an unbiased means of determining the time required for the surface to reach a specified temperature is introduced. Furthermore, it was observed that for augmented surfaces, the one dimensional conduction assumption made in the heat transfer solution is not valid for all times. Finally, treating the experimentally obtained quantities as values that are randomly distributed about some true value is not correct for all experimentally measured quantities.

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

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.

Transient Data Processing of Flow Boiling Local Heat Transfer in a Multi-Microchannel Evaporator Under a Heat Flux Disturbance

2017 ◽  
Vol 139 (1) ◽  
Author(s):  
Houxue Huang ◽  
Nicolas Lamaison ◽  
John R. Thome
Keyword(s):  
Heat Transfer ◽  
Heat Conduction ◽  
Data Reduction ◽  
Transient Flow ◽  
Flow Boiling ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Test Fluid ◽  
Computational Time ◽  
Ir Camera

Multi-microchannel evaporators are often used to cool down electronic devices subjected to continuous heat load variations. However, so far, rare studies have addressed the transient flow boiling local heat transfer data occurring in such applications. The present paper introduces and compares two different data reduction methods for transient flow boiling data in a multi-microchannel evaporator. A transient test of heat disturbance from 20 to 30 W cm−2 was conducted in a multi-microchannel evaporator using R236fa as the test fluid. The test section was 1 × 1 cm2 in size and had 67 channels, each having a cross-sectional area of 100 × 100 μm2. The micro-evaporator backside temperature was obtained with a fine-resolution infrared (IR) camera. The first data reduction method (referred to three-dimensional (3D)-TDMA) consists in solving a transient 3D inverse heat conduction problem by using a tridiagonal matrix algorithm (TDMA), a Newton–Raphson iteration, and a local energy balance method. The second method (referred to two-dimensional (2D)-controlled) considers only 2D conduction in the substrate of the micro-evaporator and solves at each time step the well-posed 2D conduction problem using a semi-implicit solver. It is shown that the first method is more accurate, while the second one reduces significantly the computational time but led to an approximated solution. This is mainly due to the 2D assumption used in the second method without considering heat conduction in the widthwise direction of the micro-evaporator.

Sign in / Sign up

Export Citation Format

Share Document