scholarly journals Thermodynamics of Fatigue: Degradation-Entropy Generation Methodology for System and Process Characterization and Failure Analysis

Entropy ◽  
2019 ◽  
Vol 21 (7) ◽  
pp. 685 ◽  
Author(s):  
Osara ◽  
Bryant
Keyword(s):  
Entropy Generation ◽  
Helmholtz Free Energy ◽  
Irreversible Thermodynamics ◽  
Design Parameters ◽  
Time To Failure ◽  
Generation Theorem ◽  
Process Characterization ◽  
Fatigue Model ◽  
Fatigue Data ◽  
New Material

Formulated is a new instantaneous fatigue model and predictor based on ab initio irreversible thermodynamics. The method combines the first and second laws of thermodynamics with the Helmholtz free energy, then applies the result to the degradation-entropy generation theorem to relate a desired fatigue measure—stress, strain, cycles or time to failure—to the loads, materials and environmental conditions (including temperature and heat) via the irreversible entropies generated by the dissipative processes that degrade the fatigued material. The formulations are then verified with fatigue data from the literature, for a steel shaft under bending and torsion. A near 100% agreement between the fatigue model and measurements is achieved. The model also introduces new material and design parameters to characterize fatigue.

scholarly journals A Thermodynamic Model for Lithium-Ion Battery Degradation: Application of the Degradation-Entropy Generation Theorem

Inventions ◽  
2019 ◽  
Vol 4 (2) ◽  
pp. 23 ◽  
Author(s):  
Jude Osara ◽  
Michael Bryant
Keyword(s):  
Lithium Ion Batteries ◽  
Lithium Ion Battery ◽  
Entropy Generation ◽  
Lithium Ion ◽  
Irreversible Thermodynamics ◽  
Design Parameters ◽  
Capacity Fade ◽  
Operational Parameters ◽  
Generation Theorem ◽  
Battery Degradation

Presented is a lithium-ion battery degradation model, based on irreversible thermodynamics, which was experimentally verified, using commonly measured operational parameters. The methodology, applicable to all lithium-ion batteries of all chemistries and composition, combined fundamental thermodynamic principles, with the Degradation–Entropy Generation theorem, to relate instantaneous capacity fade (loss of useful charge-holding capacity) in the lithium-ion battery, to the irreversible entropy generated via the underlying dissipative physical processes responsible for battery degradation. Equations relating capacity fade—aging—to battery cycling were also formulated and verified. To show the robustness of the approach, nonlinear data from abusive and inconsistent battery cycling was measured and used to verify formulations. A near 100% agreement between the thermodynamic battery model and measurements was achieved. The model also gave rise to new material and design parameters to characterize all lithium-ion batteries.

scholarly journals Reliability Evaluation of Fan-Out Type 3D Packaging-On-Packaging

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 295
Author(s):  
Pao-Hsiung Wang ◽  
Yu-Wei Huang ◽  
Kuo-Ning Chiang
Keyword(s):  
Finite Element ◽  
Thermal Cycling ◽  
Glass Substrate ◽  
High Speed ◽  
Coefficient Of Thermal Expansion ◽  
Three Dimensional ◽  
Design Parameters ◽  
Time To Failure ◽  
Wafer Level ◽  
Fine Pitch

The development of fan-out packaging technology for fine-pitch and high-pin-count applications is a hot topic in semiconductor research. To reduce the package footprint and improve system performance, many applications have adopted packaging-on-packaging (PoP) architecture. Given its inherent characteristics, glass is a good material for high-speed transmission applications. Therefore, this study proposes a fan-out wafer-level packaging (FO-WLP) with glass substrate-type PoP. The reliability life of the proposed FO-WLP was evaluated under thermal cycling conditions through finite element simulations and empirical calculations. Considering the simulation processing time and consistency with the experimentally obtained mean time to failure (MTTF) of the packaging, both two- and three-dimensional finite element models were developed with appropriate mechanical theories, and were verified to have similar MTTFs. Next, the FO-WLP structure was optimized by simulating various design parameters. The coefficient of thermal expansion of the glass substrate exerted the strongest effect on the reliability life under thermal cycling loading. In addition, the upper and lower pad thicknesses and the buffer layer thickness significantly affected the reliability life of both the FO-WLP and the FO-WLP-type PoP.

MHD and nonlinear thermal radiation effects on hybrid nanofluid past a wedge with heat source and entropy generation

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Fazle Mabood ◽  
Anum Shafiq ◽  
Waqar Ahmed Khan ◽  
Irfan Anjum Badruddin
Keyword(s):  
Heat Transfer ◽  
Differential Equations ◽  
Heat Source ◽  
Thermal Radiation ◽  
Entropy Generation ◽  
Entropy Generation Rate ◽  
Design Parameters ◽  
Hybrid Nanofluid ◽  
Nonlinear Thermal Radiation ◽  
Content Type

Purpose This study aims to investigate the irreversibility associated with the Fe3O4–Co/kerosene hybrid-nanofluid past a wedge with nonlinear radiation and heat source. Design/methodology/approach This study reports the numerical analysis of the hybrid nanofluid model under the implications of the heat source and magnetic field over a static and moving wedge with slips. The second law of thermodynamics is applied with nonlinear thermal radiation. The system that comprises differential equations of partial derivatives is remodeled into the system of differential equations via similarity transformations and then solved through the Runge–Kutta–Fehlberg with shooting technique. The physical parameters, which emerges from the derived system, are discussed in graphical formats. Excellent proficiency in the numerical process is analyzed by comparing the results with available literature in limiting scenarios. Findings The significant outcomes of the current investigation are that the velocity field uplifts for higher velocity slip and magnetic strength. Further, the heat transfer rate is reduced with the incremental values of the Eckert number, while it uplifts with thermal slip and radiation parameters. An increase in Brinkmann’s number uplifts the entropy generation rate, while that peters out the Bejan number. The results of this study are of importance involving in the assessment of the effect of some important design parameters on heat transfer and, consequently, on the optimization of industrial processes. Originality/value This study is original work that reports the hybrid nanofluid model of Fe3O4–Co/kerosene.

scholarly journals Entropy generation analysis for the design of a flat plate solar collector with fins

DYNA ◽  
2020 ◽  
Vol 87 (212) ◽  
pp. 199-208
Author(s):  
Milton Muñoz ◽  
Manuel Roa ◽  
Rodrigo Correa
Keyword(s):  
Flat Plate ◽  
Entropy Generation ◽  
Solar Collector ◽  
Entropy Generation Rate ◽  
Design Parameters ◽  
Outlet Temperature ◽  
Minimum Entropy ◽  
Airflow Velocity ◽  
Collector Plate ◽  
Flat Plate Solar Collector

This article describes the optimal design of a flat-plate solar collector with fins, based on the minimum entropy generation criterion. The design parameters were optimized, considering entropy generation due to heat transfer and airflow. The latter has not been considered in previous works. The flat plate in the collector is assimilated to a finned heat sink. The dimensionless entropy generation variation is analyzed to increase values of the number of fins, as well as for different plate thicknesses and heights. We also considered variations in airflow velocity. Our data shows that airflow velocity greatly influences entropy generation. Values other than the optimum found, caused a considerable growth of total entropy. For a collector area of 4 m2, and an outlet temperature of 50°C, the optimum parameters that minimize the entropy generation rate were: 9 fins on each side of the collector plate, a height of 5 x10-2 m, a thickness of 25x10-3m, and an air velocity variable between 0.015 and 0.046 m/s. This development is relevant to the design of flat plate solar collectors, for grain drying applications.

Thermodynamic Analysis of Latent Heat Storage in a Shell-and-Tube Heat Exchanger

1992 ◽  
Vol 114 (2) ◽  
pp. 93-99 ◽  
Author(s):  
Ch. Charach ◽  
A. Zemel
Keyword(s):  
Heat Transfer ◽  
Latent Heat ◽  
Entropy Generation ◽  
Gas Flow ◽  
Heat Storage ◽  
Cylindrical Tube ◽  
Design Parameters ◽  
Storage Process ◽  
Latent Heat Storage ◽  
Tube Heat Exchanger

This work addresses the entropy generation aspects of a latent heat storage in which the energy delivered by a hot gas flowing through a cylindrical tube induces melting of the material surrounding the tube. The heat transfer for conduction-dominated melting is analyzed, taking into account the two-dimensional effects. The storage process irreversibilities associated with both the gas flow and the heat transfer (including entropy generation in the melted layer) are considered. The number of entropy generation units, which is a measure of the thermodynamic imperfection of the energy storage process, is expressed as a function of the main design parameters of the system. Analytic bounds and simplified asymptotic expressions for this quantity are derived. The results are compared with earlier one-dimensional studies.

Entropy Analysis of a R32/CO2 Cascade Refrigeration Cycle

2014 ◽  
Vol 672-674 ◽  
pp. 1676-1679
Author(s):  
Jian Xiao ◽  
Ying Fu Liu
Keyword(s):  
Entropy Generation ◽  
Temperature Difference ◽  
Design Parameters ◽  
Refrigeration Cycle ◽  
Total Entropy ◽  
Entropy Analysis ◽  
Minimization Method ◽  
Entropy Generation Minimization ◽  
Cascade Refrigeration

In order to study the performance of a R32/CO2 cascade refrigeration cycle, entropy generation minimization method was adopted to get the influence of some important operating and design parameters on the performance of the system and entropy generations of each component and the whole system, such as the evaporating temperature(Te), the condensing temperature(Tk) and the temperature difference in the cascade condenser(ΔT). The results indicate that there are a maximum COP and a minimum total entropy generation of the system at the optimal condensing temperature of the cascade condenser when Te, Tk and ΔT are constant. The total entropy generations of the throttling device, the condenser and the compressor of HTC, the cascade condenser and the compressor of LTC are above 80% of the total entropy generation of the whole system.

Application of Degradation-Entropy Generation Theorem to Dry Sliding Friction and Wear

2008 ◽  
Author(s):  
Michael D. Bryant ◽  
Michael M. Khonsari
Keyword(s):  
Entropy Generation ◽  
Friction And Wear ◽  
Sliding Friction ◽  
Degradation Mechanism ◽  
Dry Sliding Wear ◽  
Wear Volume ◽  
Dry Sliding ◽  
Generation Theorem ◽  
Dry Sliding Friction ◽  
Wear Law

The Entropy Generation Theorem recently formulated by Bryant, Khonsari and Ling [1] relates any form of degradation to the irreversible dissipative processes germane to the degradation mechanism. The theorem was formulated and proved [1] based on the first and second laws of thermodynamics In this article, dry sliding wear will be related to dry sliding friction through application of the theorem. The result reproduces the Holm-Archard wear law, but with a wear coefficient based on measurement of temperatures and wear volume lost.

The Second Law Analysis of Thermodynamics for the Plate–Fin Surface Performance in a Cross Flow Heat Exchanger

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Mansour Nasiri Khalaji ◽  
Isak Kotcioglu ◽  
Sinan Caliskan ◽  
Ahmet Cansiz
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Heat Exchanger ◽  
Entropy Generation ◽  
Fluid Velocity ◽  
Cross Flow ◽  
Design Parameters ◽  
Second Law ◽  
Transfer Unit ◽  
Pin Fins

In this paper, a particular heat exchanger is designed and analyzed by using second law of thermodynamics. The heat exchanger operates with the cross flow forced convection having cylindrical, square, and hexagonal pin fins (tubular router) placed in the rectangular duct. The pin fins are installed periodically at the top and bottom plates of the duct perpendicular to the flow direction, structured in-line, and staggered sheet layouts. The entropy generation in the flow domain of the channels is calculated to demonstrate the rate of irreversibilities. To obtain the efficiencies, irreversibility, thermal performance factor, and entropy generation number (EGN), the heat exchanger is operated at different temperatures and flow rates by using hot and cold fluids. Optimization of the design parameters and winglet geometry associated with the performance are determined by entropy generation minimization. The variation of the EGN with Reynolds number for various tubular routers is presented. The Reynolds number is determined according to the experimental plan and the performance is analyzed with the method of effectiveness—number of transfer unit (NTU). Based on particular designs, it was determined that the increment in fluid velocity enhances the heat transfer rate, which in turn decreases the heat transfer irreversibility.

scholarly journals The Generated Entropy Monitored by Pyroelectric Sensors

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3320 ◽  
Author(s):  
Chun-Ching Hsiao ◽  
Bo-Hao Liang
Keyword(s):  
Energy Conversion ◽  
Entropy Generation ◽  
Critical Issue ◽  
Thermal Capacity ◽  
Pyroelectric Coefficient ◽  
Irreversible Processes ◽  
Entropy Generation Rate ◽  
Time To Failure ◽  
Electrode Area ◽  
Pyroelectric Sensors

Entropy generation in irreversible processes is a critical issue that affects the failure and aging of electrical, chemical or mechanical systems. The promotion of energy conversion efficiency needs to reduce energy losses, namely to decrease entropy generation. A pyroelectric type of entropy detector is proposed to monitor energy conversion processes in real time. The entropy generation rate can be derived from the induced pyroelectric current, temperature, thermal capacity, pyroelectric coefficient and electrode area. It is profitable to design entropy detectors to maintain a small thermal capacity while pyroelectric sensors minimize geometrical dimensions. Moreover, decreasing the electrode area of the PZT cells could avoid affecting the entropy variation of the measured objects, but the thickness of the cells has to be greatly reduced to promote the temperature variation rate and strengthen the electrical signals. A commercial capacitor with a capacitance of 47 μF and a maximum endured voltage of 4 V were used to estimate the entropy to act as an indicator of the capacitors’ time-to-failure. The threshold time was evaluated by using the entropy generation rates at about 7.5 s, 11.25 s, 20 s and 30 s for the applied voltages of 40 V, 35 V, 30 V and 25 V respectively, while using a PZT cell with dimensions of 3 mm square and a thickness of 200 μm.

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