Equilibrium thermodynamic theory explicitly including heat transport for evaluation of temperature distributions in steady plane-wave fronts

2001 ◽  
Vol 90 (11) ◽  
pp. 5576-5584 ◽  
Author(s):  
Tomokazu Sano ◽  
Yukio Sano
Author(s):  
Yukio Sano ◽  
Akihisa Abe

Abstract In the previous study, two Inside Temperature (ITdQ=0 and ITIM) methods for estimating the temperature distributions in steady wave fronts in a thermoviscous material were established and the ITIM method was shown qualitatively to be effective for shock compressions where the effect of viscosity was distinguished. In this paper, these two methods are applied to the shock compressions of Yittria-doped Tetragonal Zirconia (YTZ) that is a thermoviscous material with a multiple shock Hugoniot. The YTZ Hugoniot consists of three partial curves including two kinks, that are the Hugoniot Elastic Limit (HEL) and the phase transition point. The shock temperatures evaluated by the ITIM method were close to the accurate temperatures obtained by the Walsh-Christian method in the whole stress range to 140 GPa examined here. Furthermore, the inside temperature distributions were approximately accurate because the effect of viscosity was distinguished in the shock compression. By these facts, it was considered that the fundamental assumption and the assumption on heat transport used in the ITIM method were valid and as a result, this method was effective. In addition, the influence of heat transport on the temperatures and thermoelastic stresses was examined.


Author(s):  
Yukio Sano ◽  
Akihisa Abe

Abstract The purpose of this study is to establish an Inside Temperature (IT) method for estimating temperatures in steady wave fronts in a thermoviscous material. A fundamental assumption that the material in the wave front, was approximately in an equilibrium state was used in this method. A further assumption that heat transport was neglected was used in the ITdQ=0 method, while in the ITIM method, the work done by the thermal stress was offset by heat transport. Two irreversible thermodynamic equations for the temperature in the wave front derived were connected with the Hugoniot function and the Mie-Grüneisen equation, respectively. To verify the efficacy of the IT method, three temperature distributions were estimated qualitatively using an equation for entropy including no assumption on heat transport, that including the assumption used in the ITdQ=0 method, and that in the ITIM method. These three distributions suggested that the temperatures were overestimated by the ITdQ=0 method, while the ITIM method was effective for shock compressions where the effect of viscosity was distinguished.


Author(s):  
Arkadiusz Urzędowski ◽  
Joanna Styczeń ◽  
Magdalena Paśnikowska-Łukaszuk

The article presents the mechanisms of heat exchange in building partitions along with a description of the phenomena occurring there. The methods of heat transport on selected examples of the construction of sandwich building walls were presented and discussed. A review of the methods allowing to determine the heat flux value by means of analytical methods and simulations based on numerical analyzes was carried out. The methodology of solving thermal problems has been presented, indicating the complexity of the phenomena occurring at the contact points of surfaces, for which the correct characteristics should be selected in more than one selected form of determining temperature distributions. Heat transport simulation was performed in ANSYS Fluent 2020 R2 software. The value of the heat flux density flowing through the outer wall of a single-family house located in Lublin, Poland was analytically determined. Three different structural wall solutions were adopted: one, two and three-layer. The obtained results were presented in a tabular manner, allowing for a clear verification of the correctness of the calculations performed with both selected methods.


2009 ◽  
Vol 50 (2) ◽  
pp. 236-244
Author(s):  
Kenichiro Suetsugu ◽  
Atsushi Yamaguchi ◽  
Kazumi Matsushige ◽  
Toshihisa Horiuchi

Author(s):  
Yukio Sano ◽  
Akihisa Abe ◽  
Akira Yamasaki

Abstract The temperature distributions in overdriven steady wave fronts in 2024 Al shocked up to 80 GPa were predicted using the thermoelastic theory (Wallace theory), where the viscous stress is neglected, and the thermoviscous theory (Sano-Abe theory). The Wallace theory was improved by applying a more exact equation to the bulk modulus. As shock loading was increased, the difference between the temperature distributions predicted using each theory was greater. This tendency of the difference was similar for shocks up to 250 GPa in Pt. Thus, temperature distributions in overdriven steady wave fronts cannot be effectively evaluated using thermoelastic theory.


Soft Matter ◽  
2020 ◽  
Vol 16 (24) ◽  
pp. 5740-5749
Author(s):  
Yu Zhou ◽  
Lihua Jin

A non-equilibrium thermodynamic theory is developed to predict hydrolysis-induced large swelling of polyacrylamide hydrogels.


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