Fundamental Investigation of Effects of Surrounding Conditions on Measurement Uncertainty in Temperature of Surface-Mounted Components by Thermocouples

2021 ◽  
Author(s):  
Takashi Fukue ◽  
Koichi Hirasawa
Keyword(s):  
Heat Transfer ◽  
Measurement Uncertainty ◽  
Temperature Measurement ◽  
Evaluation Method ◽  
Measurement Techniques ◽  
Transfer Experiment ◽  
Pin Fin ◽  
Fundamental Investigation ◽  
Electrical Components

Abstract This study describes the development of an evaluation method of uncertainty in temperature measurement of surface-mounted components by several types of thermocouples. When thermocouples conduct the temperature measurement of the surface-mounted components, the components’ temperature decreases because the thermocouples dissipate heat like a pin fin. Temperature measurement techniques for miniaturized electrical components are strongly needed to ensure the operation’s guaranteed temperature. In this report, a heat transfer experiment around thermocouples installed on the surface of the PCBs was conducted while changing the type and the mounting angle of thermocouples. Through the temperature measurement, the decrease of the temperature around the thermocouples was confirmed.

scholarly journals Optimization of Transient Heat Transfer Measurements Using Thermochromic Liquid Crystals Based on an Error Estimation

1996 ◽  
Author(s):  
Rainer Höcker
Keyword(s):  
Heat Transfer ◽  
Liquid Crystals ◽  
Measurement Techniques ◽  
Analytical Investigation ◽  
Transient Heat Transfer ◽  
Critical Parameters ◽  
Transfer Experiment ◽  
Transfer Measurement ◽  
Thermochromic Liquid Crystals ◽  
The Individual

An analytical investigation has been made to identify and quantify critical parameters influencing the final result of a transient heat transfer experiment. The aim was to obtain a set of dimensionless parameters, that describe the interaction of the individual measured quantities in a compact form. Among the wide variety of different kinds of heat transfer measurement techniques, the transient method, employing thermochromic liquid crystals, is very useful. It gives much detailed heat transfer information with a minimum effort in experimental time. The present paper focuses on this technique, although it is not the only choice for all kinds of applications, but it is the currently most frequently used one. This paper provides the means to lay out an experiment, so that it yields acceptable results with respect to the constraints for a set of test boundary conditions.

scholarly journals VFF in MMU: Determination for Velocity of Fluid Flow in Multiphase Measurement Unit - Comparative Analysis

2021 ◽  
Vol 2 (4) ◽  
pp. 168-180
Author(s):  
Edriss Eisa Babikir Adam ◽  
Sathesh
Keyword(s):  
Heat Transfer ◽  
Temperature Measurement ◽  
Liquid Flow ◽  
Velocity Measurement ◽  
Mathematical Proof ◽  
Measurement Techniques ◽  
Measurement Unit ◽  
Particle Spectrum ◽  
Research Article ◽  
Phosphor Thermometry

The velocity measurement of liquid flow in a channel is a challenging task still. The chemical reaction and heat transfer condition are one of the internal elements of liquid for any process and production industries. Besides, the flow velocity is a significant factor to measure temperature in liquid flow. This research article reviews an overview of the velocity of fluid measurement techniques by advanced concepts in the multiphase measurement system. Based on luminescence properties, the velocity measurement is derived by large particle spectrum analysis due to laser excitation in the machine. This mathematical model analysis is used to measure the velocity of a fluid with the same particles of velocimetry. This development can be derived from the many changes of measurement factors in the heat transfer mechanism. The flowmeter design will be optimized with this mathematical proof for phosphor thermometry measurement technique. This research article contains phosphor thermometry for the measurement with implementing techniques and how this thermometry will be appropriated for temperature measurement in liquid flow. It gives the compare graphic representation for various work of temperature measurement in liquid flow of common aspects. The successful metric measurement can be ended by various intrinsic keys to the future development of the procedure. The velocity measurement performs by LDA and PIV methods. The advantages and limitations have been discussed for both the method at most recent.

Flowfield Measurements in a Single Row of Low Aspect Ratio Pin-Fins

2011 ◽  
Author(s):  
Jason K. Ostanek ◽  
Karen A. Thole
Keyword(s):  
Heat Transfer ◽  
Large Scale ◽  
Energy Transport ◽  
Measurement Techniques ◽  
Diameter Ratio ◽  
Time Resolved ◽  
Single Row ◽  
Pin Fin ◽  
Pin Fins ◽  
Pin Fin Arrays

Pin-fin arrays are commonly used as compact heat exchangers for cooling the trailing edge of gas turbine airfoils. While much research has been devoted to the heat transfer characteristics of various pin-fin configurations, little work has been done to investigate the flowfield in pin-fin arrays. Such information may allow for further optimization of pin-fin configurations. A new pin-fin facility at large scale has been constructed to allow optical access for the use of non-intrusive measurement techniques such as laser Doppler velocimetry and time-resolved, digital particle image velocimetry. Using these techniques, the flow through a single row of pin-fins having a height-to-diameter ratio of 2 and span-to-diameter ratio of 2.5 was investigated. Results show that the length of the wake region decreases with increasing Reynolds number. At higher Reynolds numbers, Ka´rma´n vortices developed closer to the pin-fins than for single, infinitely long cylinders. Transverse fluctuations correlated well with endwall heat transfer indicating that the Ka´rma´n vortices play a key role in energy transport.

Flowfield Measurements in a Single Row of Low Aspect Ratio Pin Fins

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Jason K. Ostanek ◽  
Karen A. Thole
Keyword(s):  
Heat Transfer ◽  
Large Scale ◽  
Energy Transport ◽  
Measurement Techniques ◽  
Diameter Ratio ◽  
Time Resolved ◽  
Single Row ◽  
Pin Fin ◽  
Pin Fins ◽  
Pin Fin Arrays

Pin-fin arrays are commonly used as compact heat exchangers for cooling the trailing edge of gas turbine airfoils. While much research has been devoted to the heat transfer characteristics of various pin-fin configurations, little work has been done to investigate the flowfield in pin-fin arrays. Such information may allow for further optimization of pin-fin configurations. A new pin-fin facility at large scale has been constructed to allow optical access for the use of nonintrusive measurement techniques such as laser Doppler velocimetry and time-resolved, digital particle image velocimetry. Using these techniques, the flow through a single row of pin fins having a height-to-diameter ratio of 2 and span-to-diameter ratio of 2.5 was investigated. Results showed that the length of the wake region decreased with increasing Reynolds number. At higher Reynolds numbers, Kármán vortices developed closer to the pin fins than for single, infinitely long cylinders. Transverse fluctuations correlated well with endwall heat transfer indicating that the Kármán vortices play a key role in energy transport.

Identification of Unknown Heating Elements Embedded in a Rectangular Package

2005 ◽  
Vol 127 (8) ◽  
pp. 918-930 ◽  
Author(s):  
Chin-Hsiang Cheng ◽  
Mei-Hsia Chang
Keyword(s):  
Heat Transfer ◽  
Measurement Uncertainty ◽  
Temperature Measurement ◽  
Thermal Conditions ◽  
Grid Size ◽  
Identification Accuracy ◽  
Inverse Heat Transfer ◽  
Different Shapes ◽  
Effects Of Temperature ◽  
Transfer Method

The aim of this study is to present a novel inverse heat transfer method, which incorporates an automatic-filter scheme with the conjugate gradient method, for identifying shapes and temperatures of heating elements embedded in a rectangular package. In this report, shapes of the heating elements are visualized by using node-matrix images. A group of unknown heating elements with different shapes, positions, and temperatures are nondestructively identified simply based on the data of the upper surface temperature of the rectangular package. Effects of temperature measurement uncertainty, grid size, and number of measurement points on the top surface on the identification accuracy are evaluated. Results show that the geometric and thermal conditions of the embedded heating elements can be predicted precisely by using the present approach. The approach is found to be stable and insensitive to the temperature measurement uncertainty, and, without overwhelming mathematical manipulation, the form of objective function becomes flexible.

EFFECTS OF PIN FIN CONFIGURATIONS ON HEAT TRANSFER AND FRICTION FACTOR IN AN IMPROVED LAMILLOY COOLING STRUCTURE

2017 ◽  
Vol 48 (7) ◽  
pp. 657-679 ◽  
Author(s):  
Lei Luo ◽  
Chenglong Wang ◽  
Lei Wang ◽  
Bengt Sunden ◽  
Songtao Wang
Keyword(s):  
Heat Transfer ◽  
Friction Factor ◽  
Pin Fin

scholarly journals Efficiency Improvement of Miniaturized Heat Exchangers

Fluids ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 25
Author(s):  
Iris Gerken ◽  
Thomas Wetzel ◽  
Jürgen J. Brandner
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Heat Exchangers ◽  
Assessment Method ◽  
Flow Path ◽  
Transfer Enhancement ◽  
Pressure Losses ◽  
Pin Fin ◽  
Additional Pressure ◽  
The Impact

Micro heat exchangers have been revealed to be efficient devices for improved heat transfer due to short heat transfer distances and increased surface-to-volume ratios. Further augmentation of the heat transfer behaviour within microstructured devices can be achieved with heat transfer enhancement techniques, and more precisely for this study, with passive enhancement techniques. Pin fin geometries influence the flow path and, therefore, were chosen as the option for further improvement of the heat transfer performance. The augmentation of heat transfer with micro heat exchangers was performed with the consideration of an improved heat transfer behaviour, and with additional pressure losses due to the change of flow path (pin fin geometries). To capture the impact of the heat transfer, as well as the impact of additional pressure losses, an assessment method should be considered. The overall exergy loss method can be applied to micro heat exchangers, and serves as a simple assessment for characterization. Experimental investigations with micro heat exchanger structures were performed to evaluate the assessment method and its importance. The heat transfer enhancement was experimentally investigated with microstructured pin fin geometries to understand the impact on pressure loss behaviour with air.

Sign in / Sign up

Export Citation Format

Share Document