scholarly journals Measurement Method of Thermal Conductivity in Non-uniform and High Temperature Field

Netsu Bussei ◽  
2020 ◽  
Vol 34 (4) ◽  
pp. 137-146
Author(s):  
Takahiro Ohmura ◽  
Kento Ishii ◽  
Taichi Tasaka ◽  
Akira Kondo ◽  
Makio Naito
Keyword(s):  
Thermal Conductivity ◽  
Temperature Field ◽  
High Temperature ◽  
Measurement Method

scholarly journals Measurement Method of Thermal Conductivity in Ununiformed Temperature Field

Netsu Bussei ◽  
2017 ◽  
Vol 31 (4) ◽  
pp. 166-173 ◽  
Author(s):  
Takahiro Ohmura ◽  
Tseng-Wen Lian ◽  
Akira Kondo ◽  
Ryo Hayasaka ◽  
Makio Naito
Keyword(s):  
Thermal Conductivity ◽  
Temperature Field ◽  
Measurement Method

scholarly journals High Temperature Thermal Properties of Bentonite Foundry Sand

2015 ◽  
Vol 15 (2) ◽  
pp. 47-50 ◽  
Author(s):  
P.K. Krajewski ◽  
J.S. Suchy ◽  
G. Piwowarski ◽  
W.K. Krajewski
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Temperature Field ◽  
Thermal Properties ◽  
High Temperature ◽  
Mould Temperature ◽  
Green Sand ◽  
Foundry Sand ◽  
Temperature Range ◽  
Water Vaporization

Abstract The paper presents results of measuring thermal conductivity and heat capacity of bentonite foundry sand in temperature range ambient - 900­­°C. During the experiments a technical purity Cu plate was cast into the green-sand moulds. Basing on measurements of the mould temperature field during the solidification of the casting, the temperature relationships of the measured properties were evaluated. It was confirmed that water vaporization strongly influences thermal conductivity of the moulding sand in the first period of the mould heating by the poured casting.

Numerical and Experimental Research on the Feasibility for Plasma Arc Forming of Laminated Clad Metal Sheets Containing Defects

2012 ◽  
Vol 217-219 ◽  
pp. 1552-1555
Author(s):  
Wen Qing Song ◽  
Wen Ji Xu ◽  
Jing Fu Chai
Keyword(s):  
Thermal Conductivity ◽  
Stainless Steel ◽  
Temperature Field ◽  
High Temperature ◽  
Mild Steel ◽  
Partial Melting ◽  
Experimental Research ◽  
Plasma Arc ◽  
Sharp Rise ◽  
Metal Sheets

In this paper, a FEM mode was developed to study the feasibility of the plasma arc bending of the laminated clad metal sheets (LCMS) containing defects. The three layer LCMS of stainless steel/mild steel/stainless steel was selected as the sample. The influences of the defects on the temperature field and deformation field were investigated. Besides, the bending experiments were performed to examine the feasibility. The results show that there is a sharp rise of temperature around the defect due to the lower thermal conductivity which causes the possible partial melting of the formed parts. The existence of the defect exacerbates the unevenness of the thickness along the heating line. But the delamination of the interface does not occur because of the instantaneous variations of the stress under the high temperature, which is consistent with the experiments.

Analysis of significant measures for thermal conductivity

2020 ◽  
pp. 35-42
Author(s):  
Yuri P. Zarichnyak ◽  
Vyacheslav P. Khodunkov
Keyword(s):  
Thermal Conductivity ◽  
Heat Flux ◽  
Surface Heat Flux ◽  
Heat Flux Density ◽  
Measurement Method ◽  
Conductivity Measurement ◽  
Surface Heat ◽  
Measuring Instrument ◽  
New Class ◽  
Achievable Accuracy

The analysis of a new class of measuring instrument for heat quantities based on the use of multi-valued measures of heat conductivity of solids. For example, measuring thermal conductivity of solids shown the fallacy of the proposed approach and the illegality of the use of the principle of ambiguity to intensive thermal quantities. As a proof of the error of the approach, the relations for the thermal conductivities of the component elements of a heat pump that implements a multi-valued measure of thermal conductivity are given, and the limiting cases are considered. In two ways, it is established that the thermal conductivity of the specified measure does not depend on the value of the supplied heat flow. It is shown that the declared accuracy of the thermal conductivity measurement method does not correspond to the actual achievable accuracy values and the standard for the unit of surface heat flux density GET 172-2016. The estimation of the currently achievable accuracy of measuring the thermal conductivity of solids is given. The directions of further research and possible solutions to the problem are given.

WIELAND-K88

Alloy Digest ◽  
2005 ◽  
Vol 54 (12) ◽  
Keyword(s):  
Thermal Conductivity ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Stress Relaxation ◽  
Copper Alloy ◽  
Elevated Temperatures ◽  
Heat Treating ◽  
Relaxation Resistance ◽  
Temperature Performance ◽  
Very High

Abstract Wieland K-88 is a copper alloy with very high electrical and thermal conductivity, good strength, and excellent stress relaxation resistance at elevated temperatures. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: CU-738. Producer or source: Wieland Metals Inc.

High‐Temperature Skin Softening Materials Overcoming the Trade‐Off between Thermal Conductivity and Thermal Contact Resistance

Small ◽  
2021 ◽  
pp. 2102128
Author(s):  
Taehun Kim ◽  
Seongkyun Kim ◽  
Eungchul Kim ◽  
Taesung Kim ◽  
Jungwan Cho ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
High Temperature ◽  
Contact Resistance ◽  
Thermal Contact Resistance ◽  
Thermal Contact ◽  
Trade Off

scholarly journals High-Temperature Elastic Properties of Yttrium-Doped Barium Zirconate

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 968
Author(s):  
Fumitada Iguchi ◽  
Keisuke Hinata
Keyword(s):  
High Temperature ◽  
Young’S Modulus ◽  
Elastic Properties ◽  
Measurement Method ◽  
Young's Modulus ◽  
Barium Zirconate ◽  
Shear Moduli ◽  
Ceramic Fuel ◽  
Yttrium Concentration ◽  
Ceramic Fuel Cells

The elastic properties of 0, 10, 15, and 20 mol% yttrium-doped barium zirconate (BZY0, BZY10, BZY15, and BZY20) at the operating temperatures of protonic ceramic fuel cells were evaluated. The proposed measurement method for low sinterability materials could accurately determine the sonic velocities of small-pellet-type samples, and the elastic properties were determined based on these velocities. The Young’s modulus of BZY10, BZY15, and BZY20 was 224, 218, and 209 GPa at 20 °C, respectively, and the values decreased as the yttrium concentration increased. At high temperatures (>20 °C), as the temperature increased, the Young’s and shear moduli decreased, whereas the bulk modulus and Poisson’s ratio increased. The Young’s and shear moduli varied nonlinearly with the temperature: The values decreased rapidly from 100 to 300 °C and gradually at temperatures beyond 400 °C. The Young’s modulus of BZY10, BZY15, and BZY20 was 137, 159, and 122 GPa at 500 °C, respectively, 30–40% smaller than the values at 20 °C. The influence of the temperature was larger than that of the change in the yttrium concentration.

Design of a Steady-State, Parallel-Plate Thermal Conductivity Apparatus for Nanofluids and Comparative Measurements With Transient HWTC Apparatus

2010 ◽  
Author(s):  
Milivoje M. Kostic ◽  
Casey J. Walleck
Keyword(s):  
Thermal Conductivity ◽  
Steady State ◽  
Parallel Plate ◽  
Measurement Method ◽  
Mixture Theory ◽  
Hot Wire ◽  
Electro Magnetic ◽  
Magnetic Phenomena ◽  
Thermal Conductivities

A steady-state, parallel-plate thermal conductivity (PPTC) apparatus has been developed and used for comparative measurements of complex POLY-nanofluids, in order to compare results with the corresponding measurements using the transient, hotwire thermal conductivity (HWTC) apparatus. The related measurements in the literature, mostly with HWTC method, have been inconsistent and with measured thermal conductivities far beyond prediction using the well-known mixture theory. The objective was to check out if existing and well-established HWTC method might have some unknown issues while measuring TC of complex nano-mixture suspensions, like electro-magnetic phenomena, undetectable hot-wire vibrations, and others. These initial and limited measurements have shown considerable difference between the two methods, where the TC enhancements measured with PPTC apparatus were about three times smaller than with HWTC apparatus, the former data being much closer to the mixture theory prediction. However, the influence of measurement method is not conclusive since it has been observed that the complex nano-mixture suspensions were very unstable during the lengthy steady-state measurements as compared to rather quick transient HWTC method. The nanofluid suspension instability might be the main reason for very inconsistent results in the literature. It is necessary to expend investigation with more stable nano-mixture suspensions.

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