scholarly journals Basic Equation for the Different Coupled Equations between the First and Second Laws of Thermodynamics at Strong Coupling

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Saeed Shahsavari
Keyword(s):  
Internal Energy ◽  
Strong Coupling ◽  
Basic Equation ◽  
Structure Theory ◽  
Dissipated Energy ◽  
Second Law ◽  
Energy Structure ◽  
Coupled Equations ◽  
Laws Of Thermodynamics ◽  
Energy Dissipated

For some physical processes, the first and second laws of thermodynamics can be at strong coupling. Also, it is possible that the familiar inequalities of macroscopic thermodynamics cannot be used in the analysis of the system, and it is needed that the inequalities rewrote as equalities. In these cases, the work, internal energy, dissipated energy, and entropy production must be considered and identified together. In this paper, the basic equation for the different coupled equations between the first and second laws of thermodynamics at strong coupling is extracted. Also, inspired by the first and second laws of thermodynamics and different approaches to the second law, a thermophysical equation for thermodynamics is extracted. This equation can be used instead of the first and second laws of thermodynamics as to the analysis of the performed process these laws must be established together. It is tried that effective internal energy, directly to be related to the entropy or vice versa, in one general equation. Also, the presented equation is in the same line with the different approaches to the second law and energy structure theory.  

First and second laws of thermodynamics: relationship, “inconsistency”, hidden effects

2020 ◽  
pp. 63-73
Author(s):  
A. M. Savchenko ◽  
Yu. V. Konovalov ◽  
A. V. Laushkin
Keyword(s):  
Free Energy ◽  
Internal Energy ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Entropy Of Mixing ◽  
Ideal Mixing ◽  
Laws Of Thermodynamics ◽  
Relationship Of ◽  
The Relationship

The relationship of the first and second laws of thermodynamics based on their energy nature is considered. It is noted that the processes described by the second law of thermodynamics often take place hidden within the system, which makes it difficult to detect them. Nevertheless, even with ideal mixing, an increase in the internal energy of the system occurs, numerically equal to an increase in free energy. The largest contribution to the change in the value of free energy is made by the entropy of mixing, which has energy significance. The entropy of mixing can do the job, which is confirmed in particular by osmotic processes.

scholarly journals On the Irreversibility in Mechanical Systems Using a New Macroscopic Energy Structure Modeling

2020 ◽  
Vol 8 (6) ◽  
Author(s):  
Saeed Shahsavari ◽  
Mehran Moradi ◽  
Morteza Esmaeilpour
Keyword(s):  
Irreversible Process ◽  
Statistical Approach ◽  
Mechanical Systems ◽  
Second Law Of Thermodynamics ◽  
Dissipated Energy ◽  
Second Law ◽  
Energy Structure ◽  
Performance Effects ◽  
New Energy ◽  
Energy Components

This paper presents a macroscopic applied innovate modeling to study the performance effects of the second law of thermodynamics on the mechanical systems. To investigate the irreversibility in mechanical systems, the energy structure of the system can be studied. Some energy components relate to the reversible processes and remaining relate to the irreversible process. Exiting models are based on the studying sub structures and therefore, need a large volume of the calculations. In this paper, at first, using a macroscopic quasi-statistical approach, a new energy structure equation is extracted and by examining it’s variation in the different paths, the irreversible components as well as their structures are studied. Using the kinematic theories of dissipated energy, it can be concluded that the extracted equations have the same base as the different formulations of the second law of thermodynamics. Finally, as a mechanical system example with the possibility of irreversibility in the possible performed processes, the extracted equations are developed for viscoelasticity problems. And also the matching of the results with expected results is shown.

Balance of energy and entropy imbalance

2020 ◽  
pp. 85-90
Author(s):  
Lallit Anand ◽  
Sanjay Govindjee
Keyword(s):  
Free Energy ◽  
Kinetic Energy ◽  
Internal Energy ◽  
Rate Of Change ◽  
The Body ◽  
Mechanical Power ◽  
Second Law ◽  
Entropy Flow ◽  
Energy Plus ◽  
Laws Of Thermodynamics

This chapter discusses the first and second laws of thermodynamics. The first law represents a balance between the rate of change of the internal energy plus the rate of change of kinetic energy of a part of the body, and the rate at which energy in the form of heat is transferred to the part plus the mechanical power expended upon it. A part also possesses entropy, and the second law is the statement that the rate at which the net entropy of a part changes is greater than or at a minimum equal to the entropy flow into the part, resulting in a free energy imbalance known as the Clausius-Duhem inequality.

scholarly journals Experimental and Numerical Study of Fracture Behavior of Rock-Like Material Specimens with Single Pre-Set Joint under Dynamic Loading

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2690
Author(s):  
Bo Pan ◽  
Xuguang Wang ◽  
Zhenyang Xu ◽  
Lianjun Guo ◽  
Xuesong Wang
Keyword(s):  
Crack Initiation ◽  
Crack Propagation ◽  
Joint Angle ◽  
Simulation Software ◽  
Dissipated Energy ◽  
Energy Structure ◽  
Joint Angles ◽  
Crack Penetration ◽  
Before And After ◽  
The Impact

The Split Hopkinson Pressure Bar (SHPB) is an apparatus for testing the dynamic stress-strain response of the cement mortar specimen with pre-set joints at different angles to explore the influence of joint attitudes of underground rock engineering on the failure characteristics of rock mass structure. The nuclear magnetic resonance (NMR) has also been used to measure the pore distribution and internal cracks of the specimen before and after the testing. In combination with numerical analysis, the paper systematically discusses the influence of joint angles on the failure mode of rock-like materials from three aspects of energy dissipation, microscopic damage, and stress field characteristics. The result indicates that the impact energy structure of the SHPB is greatly affected by the pre-set joint angle of the specimen. With the joint angle increasing, the proportion of reflected energy moves in fluctuation, while the ratio of transmitted energy to dissipated energy varies from one to the other. NMR analysis reveals the structural variation of the pores in those cement specimens before and after the impact. Crack propagation direction is correlated with pre-set joint angles of the specimens. With the increase of the pre-set joint angles, the crack initiation angle decreases gradually. When the joint angles are around 30°–75°, the specimens develop obvious cracks. The crushing process of the specimens is simulated by LS-DYNA software. It is concluded that the stresses at the crack initiation time are concentrated between 20 and 40 MPa. The instantaneous stress curve first increases and then decreases with crack propagation, peaking at different times under various joint angles; but most of them occur when the crack penetration ratio reaches 80–90%. With the increment of joint angles in specimens through the simulation software, the changing trend of peak stress is consistent with the test results.

scholarly journals Fluctuating Diffusivity of RNA-Protein Particles: Analogy with Thermodynamics

Entropy ◽  
2021 ◽  
Vol 23 (3) ◽  
pp. 333
Author(s):  
Yuichi Itto
Keyword(s):  
Internal Energy ◽  
Messenger Rna ◽  
Living Cells ◽  
Statistical Fluctuation ◽  
Rna Molecules ◽  
Average Value ◽  
Thermodynamic Entropy ◽  
Laws Of Thermodynamics ◽  
Protein Particles ◽  
Quantity Of Heat

A formal analogy of fluctuating diffusivity to thermodynamics is discussed for messenger RNA molecules fluorescently fused to a protein in living cells. Regarding the average value of the fluctuating diffusivity of such RNA-protein particles as the analog of the internal energy, the analogs of the quantity of heat and work are identified. The Clausius-like inequality is shown to hold for the entropy associated with diffusivity fluctuations, which plays a role analogous to the thermodynamic entropy, and the analog of the quantity of heat. The change of the statistical fluctuation distribution is also examined from a geometric perspective. The present discussions may contribute to a deeper understanding of the fluctuating diffusivity in view of the laws of thermodynamics.

scholarly journals Dynamics of Assembled Structures: Taking Into Account the Surface Defects in Interfaces

2013 ◽  
Author(s):  
Nicolas Peyret ◽  
Gaël Chevallier ◽  
Jean-Luc Dion
Keyword(s):  
Loss Factor ◽  
Surface Defect ◽  
Test Bench ◽  
Surface Defects ◽  
Dissipated Energy ◽  
Energy Losses ◽  
Proposed Model ◽  
Nonlinear Loss ◽  
Energy Dissipated ◽  
Experimental Bench

In structural dynamics, the prediction of damping remains the biggest challenge. This paper deals with the energy losses caused by micro-slip in a nominally planar interface of a structure. This paper proposes an analytical and experimental study of flexural vibrations of a clamped-clamped beam with innovative position of the interfaces. The objective of this test bench is to characterize the global rheology of the interface. The proposed model aims to characterize this rheology based on local settings of the interface. First, the test bench is described and the choice of the position of the interface is justified. The experimental bench and the dynamic behavior of this structure are presented. We propose to illustrate the mechanism of energy losses by micro-slip by making a comparison between the behavior of a “monolithic” beam and a sectioned beam. Secondly, a modeling of the interface taking into account the surface defect is presented. The energy dissipated by friction in the interface is calculated during a loading cycle. This leads to a computation of the dissipated energy and thus to a nonlinear loss factor. Finally, we confront the loss factor calculated analytically and the measured one.

An Energy Approach for Helping the Selection of Solid Lubrication Coatings Under Fretting Conditions

2009 ◽  
Author(s):  
D. B. Luo ◽  
V. Fridrici ◽  
Ph. Kapsa ◽  
M. Taillandier ◽  
C. Prud’homme
Keyword(s):  
Master Curve ◽  
Initial Energy ◽  
Energy Approach ◽  
Friction Reduction ◽  
Solid Lubrication ◽  
Dissipated Energy ◽  
Test Parameters ◽  
Definition Of ◽  
Energy Dissipated ◽  
Fretting Damage

Employing friction reduction coatings is one of the most effective methods to palliate the fretting damage. However, facing numerous available coatings, how to compare them and select the optimum one for a specific application is still a challenging task. In this paper, based on the investigation of the fretting behaviors of several bonded solid lubricant coatings, an energy approach in terms of “initial maximal dissipated energy density” was suggested to compare the tribological response of coatings. According to test results, the lifetime of each coating under different test parameters can be fitted by one master curve. The definition of this master curve for a given coating may be used for the prediction of the coating lifetime only by knowing the initial energy dissipated in the contact. The comparison of different master curves for different coatings can be employed to help the coating selection.

Optimal Vibration Control and Energy Scavenging Using Collocated Nonlinear Energy Sinks and Piezoelectric Elements

2018 ◽  
Author(s):  
Zahra Nili Ahmadabadi ◽  
Siamak Esmaeilzadeh Khadem
Keyword(s):  
Piezoelectric Element ◽  
Dissipated Energy ◽  
Vibration Energy ◽  
Energy Scavenging ◽  
Optimization Approach ◽  
Energy Harvesters ◽  
Energy Pumping ◽  
Nonlinear Energy Pumping ◽  
Energy Dissipated ◽  
Nonlinear Energy

This paper presents an optimal design for a system comprising multiple nonlinear energy sinks (NESs) and piezoelectric-based vibration energy harvesters attached to a free–free beam under shock excitation. The energy harvesters are used for scavenging vibration energy dissipated by the NESs. Grounded and ungrounded configurations are examined, and the systems parameters are optimized globally to maximize the dissipated energy by the NESs. The performance of the system was optimized using a dynamic optimization approach. Compared to the system with only one NES, using multiple NESs resulted in a more effective realization of nonlinear energy pumping particularly in the ungrounded configuration. Having multiple piezoelectic elements also increased the harvested energy in the grounded configuration relative to the system with only one piezoelectric element.

scholarly journals XVI. Some applications of dynamical principles to physical phenomena.—Part II

1887 ◽  
Vol 178 ◽  
pp. 471-526 ◽  
Keyword(s):  
Direct Application ◽  
Second Law ◽  
Conservation Of Energy ◽  
Laws Of Thermodynamics ◽  
William Thomson ◽  
Physical Phenomena ◽  
Dynamical Principle

1. The two laws of Thermodynamics have proved by far the most powerful, indeed almost the only, means we possess of connecting the phenomena in one branch of Physics with those in another. Though the two laws are usually grouped together, it should not be forgotten that they differ essentially in character. The First Law is a direct application to Physics of one of the most important dynamical principles, that of the Conservation of Energy; while the Second Law, which for the purpose of connecting various physical phenomena is even more important than the first, is not, strictly speaking, a dynamical principle at all, since its statement involves a reference to quantities which never occur in abstract Dynamics. Clausius and Sir William Thomson, the two physicists to whom the Second Law owes its importance, have connected it with other principles which seem more axiomatic.

A Micro Combined Heat and Power Thermodynamic Analysis and Optimization

2010 ◽  
Author(s):  
Ali Gholizadeh ◽  
M. B. Shafii ◽  
M. H. Saidi
Keyword(s):  
Combustion Chamber ◽  
Entropy Production ◽  
Thermodynamic Analysis ◽  
Second Law Of Thermodynamics ◽  
Combined Heat And Power ◽  
Second Law ◽  
Entropy Production Rate ◽  
Prime Mover ◽  
Operation Condition ◽  
Laws Of Thermodynamics

In modeling and designing micro combined heat and power cycle most important point is recognition of how the cycle operates based on the first and second laws of thermodynamics simultaneously. Analyzing data obtained from thermodynamic analysis employed to optimize MCHP cycle. The data obtained from prime mover optimization has been used for basic stimulus cycle. Assumptions considered for prime mover optimization has been improved, for example in making optimum operation condition by using genetic algorithms constant pressure combustion chamber was considered. The exact value of downstream and upstream pressure changes in the combustion chamber reaction has been obtained. After extraction of the appropriate relationship for the primary stimulus cycle, data required for the overall cycle analysis identified, By using these data optimum total cycle efficiency and constructing the first and second laws of thermodynamics has been calculated for it. After reviewing Thermodynamic governing relations in each cycle and using the optimum values that the prime mover has been optimized with, other cycles have been optimized. In best performance condition of cycle, electrical efficiency was 41 percent and the overall efficiency of the cycle was 88 percent, respectively. After using the second law of thermodynamics mathematical model Second law of thermodynamics efficiency and entropy production rate was estimated. Second law of thermodynamics yield best performance against the 45.14 percent and the rate of entropy production in this case equal to 0.099 kW/K respectively.

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