Apuntes termodinamica

Content of Lecture 1:"Thermodynamic Approach to States and Processes:

Concepts, Methods and Fundamental Results"

Prof. Javier Martínez MardonesInstituto de Física

1.1 Thermodynamics: The Science of States and Processes. Targets and Areas of Study. Methodology and Philosophy. Historical Background. Branches and Development of Thermodynamics.

1.2 Energetics in Mechanics and the First Law of Thermodynamics: A Summary of Key Points. Work and Kinetic Energy. Potential Energy. Conservation of Mechanical Energy. The First Law for Closed Systems. The Message of the First Law. Consequences and Generalizations. Application: the Enthalpy Function.

1.3 The Direction of the Natural Changes. Reversible and Irreversible Processes.Heat Flow and Conversion of Work into Heat. The Carnot Engine: Key Results. The Second Law. Statements of Kelvin-Planck and Clausius. Equivalence. The Message of the Second Law of Thermodynamics.

1.4 Consequences of the Second Law. The Clausius Theorem. Application to Reversible Cycles. Entropy Difference between Two Equilibrium States. Application to an Arbitrary Process. Differential forms of the Clausius Theorem: Uncompensated Heat. Processes in a Closed System with Defined Temperature. Applications: Heat Reservoirs and Isolated Systems.

1.5 Entropy Change and Irreversible Processes. Contributions to the Entropy Change. Entropy Production and Entropy Flow.

The Second Law expressed as an Equality. Summary and Remarks.

1.1 THERMODYNAMICS: THE SCIENCE OF STATES AND PROCESSES

1.1.1 Targets and Areas of Study

• The macroscopic properties of material systems.

• The Mechanical, Thermal and Chemical (MTC) interactions between a system and another system or its surroundings.

• The various processes of change in the macroscopic properties of the systems.

1.1.2 Methodology and Philosophy

• Experimental interrogation of nature. Acting on the material systems and measuring the effects (the answer of the system).

• The universe of operations of Thermodynamics: (a) laboratory operations

• with macroscopic instruments and long time ‑measurements; (b) paper and pencil operations.

• Results: A few general statements, the Laws of Thermodynamics. These are independent of the theoretical models of the microscopic structure of matter.

• These Laws summarize our knowledge of the macroscopic behaviour of the real systems. In particular, they capture two basic experiences: (a) The existence of correlations between the results of operations on macroscopic systems and (b) the tendency of the systems to evolve towards rest and of the changes to decay and "die out".

• On the basis of these Laws, new predictions can be made. Key feature: interaction between theory and experiments.

1.1.3 Background

• Established as a discipline in the 1850's and 1860's.

• Context: Expansion of the experimental knowledge of nature initiated in 1800. New phenomena and connections between various phenomena. The idea of the unity of nature.

• The problem of the efficiency of the heat engines. Conversion of Heat into Work. The role of enginneering concepts in the development of Thermodynamics.

• A long-standing problem: the kinetic nature of heat and matter.

EquilibriumEquilibriumClose to

Equilibrium: Stationary

Close to Equilibrium:

StationaryFar from

EquilibriumFar from

Equilibrium

Thermodynamics: Science of Status and processesThermodynamics: Science of Status and processes

States of the SystemStates of the System

EquilibriumThermodynamics

EquilibriumThermodynamics

Non-Linear Irreversible

Thermodynamics

Non-Linear Irreversible

Thermodynamics

Linear Irreversible

Thermodynamics

Linear Irreversible

Thermodynamics

ReversibleReversibleTransport and some chemical

reactions

Transport and some chemical

reactions

Various Irreversible Phenomena

Various Irreversible Phenomena

Processes Occurring in the System Processes Occurring in the System

1.1.4 Branches and Development of Thermodynamics

(I) Equilibrium States and Reversible Processes

(a) Classical Thermodynamics

Key names: Carnot, Mayer, Helmholtz, Joule, Clausius, Thomson (Lord Kelvin).

Key issues and concepts:• Systems and Surroundings.• Efficiency of heat engines.• Relations between Heat and Work.• Energy and Entropy.

(b) Chemical Thermodynamics

Key names: Gibbs, Duhem, Van't Hoff, Nernst, Le Chatelier, Lewis.

Key issues and concepts:• Properties and States of Systems.• Thermodynamic potentials.• Physico-chemical equilibrium and stability. • The direction of the physico-chemical processes

and reactions.

(II) Linear Irreversible Thermodynamics

Key names: de Donder, Bridgman, Eckart, Tolman, Meixner, Onsager, Prigogine, de Groot, Mazur.

Key issues and concepts:• Entropy production.• Affinities (Forces) and Rates (Flows).• Phenomenological relations.• Reciprocity relations.

(III) Non-Linear Irreversible Thermodynamics

Key names in the Local-equilibrium approach: Prigogine and his school.

Key issues and concepts:• Stability considerations.• Evolution criteria.• Fluctuations.• Instabilities. Dissipative structures.

1.2 ENERGETICS IN MECHANICS AND THE FIRST LAW OF THERMODYNAMICS: A SUMMARY OF KEY POINTS

1.2.1 Work and Kinetic Energy

1.2.2 Potential Energy

1.2.3 Conservation of Mechanical Energy

1.2.4 The First Law for Closed Systems

1.2.5 The Message of the First Law

1.2.6 Consequences and Generalizations

1.2.7 Application: the Enthalpy Function

1.2.1 Work and Kinetic Energy

1.2.2 Potential Energy

1.2.3 Conservation of Mechanical Energy.

In the particular case of a Conservative System

1.2.4 The First Law for Closed Systems

1.2.5 The First Law for Closed Systems

1.2.6 Consequences and Generalizations

1.2.7 Application: The Enthalpy Function

1.3 THE DIRECTION OF THE NATURAL CHANGE: THE

SECOND LAW

1.3.1 Reversible and Irreversible Processes.

1.3.2 The Carnot Engine: Key Results.

1.3.3 The Second Law: Classical Statements

1.3.4 The Message of the Second Law of Thermodynamics.

1.3.1 Reversible and Irreversible Processes

1.3.2 The Carnot Engine

1.3.3 The Second Law: Classical Statements.

1.3.4 The Message of the Second Law

1.4 CONSEQUENCES OF THE SECOND LAW :

ENTROPY

1.4.1 The Clausius Theorem.

1.4.2 Application to Reversible Cycles: Entropy Difference

between Equilibrium States.

1.4.3 Application to an Arbitrary Process.

1.4.4 Differential forms of the Clausius Theorem:

Uncompensated Heat.

1.4.5 Processes in a Closed System with Defined

Temperature.

1.4.6 Applications: Heat Reservoirs and Isolated Systems.

1.4.1 The Clausius Theorem

1.4.2 Application to Reversible Cycles: Entropy Difference between Equilibrium States

1.4.3 Application to an Arbitrary Process

1.4.4 Differential Forms of the Clausius Theorem: Uncompensated Heat

1.4.5 Processes in a Closed System with a Defined Temperature.

1.4.6 Application: Heat Reservoirs and Isolated Systems

1.5 ENTROPY CHANGE AND IRREVERSIBLE

PROCESSES

1.5.1 Contributions to the Entropy Change

1.5.2 The Clausius Theorem Expressed as an Equality

1.5.3 Summary and Remarks

1.5.1 Contributions to the Entropy Change

1.5.2 The Clausius Theorem Expressed as an Equality

1.5.3 Summary and Remarks

Content of Lecture 1:"Thermodynamic Approach to States and Processes:

Concepts, Methods and Fundamental Results"

Prof. Javier Martínez MardonesInstituto de Física