Thermodynamics Lecture 1

Introduction

Thermodynamics: Originates from Greek words "therme" (heat) and "dynamic" (force).
Early focus: Power from hot bodies, ability of heat to do work.
Modern scope: Broader, involving many physical processes.

Thermodynamics in everyday life and various spontaneous and influenced processes.
Processes occur with a specific rhythm, not arbitrarily.
- e.g., Water flows downhill, heat flows from hot to cold.
- Mechanical energy converts to intermolecular energy when stopped, but not the reverse.
- Processes like heating/cooling, expansion/compression occur in both directions but affect surroundings.

Conservation of Energy: Energy cannot be created or destroyed but transformed (1st Law of Thermodynamics).
Directional Constraints: Not all energy conversions are efficient or possible in reverse directions.
100% Conversion: Physically impossible for heat to work, even in ideal systems.

Efficient energy utilization and conservation due to fossil fuel depletion.
Seeking alternative energy resources with efficiency and minimal environmental impact.
Thermodynamics helps in understanding which processes are feasible.

Macroscopic (Classical) View: Focuses on bulk properties, measured directly e.g., pressure, volume, temperature.
Microscopic (Statistical) View: Analyzes molecular actions, relates to macroscopic behavior.

Introduction: Definitions, systems and surroundings, thermodynamic properties, equilibrium, concepts of energy, work, and heat transfer.
First Law of Thermodynamics: Energy conservation for closed/open systems, internal energy, enthalpy, specific heats.
Second Law of Thermodynamics: Directional constraints, reversibility, Carnot’s principle, entropy, entropy balance, Clausius inequality.
Availability: Definitions and balance for closed/open systems, irreversibility, second law efficiency.
Thermodynamic Property Relations: Maxwell’s equations, Tds equations, Joule-Kelvin effect.
Properties of Pure Substances: Phase equilibrium diagram, thermodynamic planes, steam tables, Mollier diagram, Clausius Clapeyron equation.
Properties of Gases and Gas Mixtures: Ideal gas laws, Avogadro’s law, internal energy, entropy change of an ideal gas.
Thermodynamics of Reactive Systems: Analysis, enthalpy of reaction and formation, reaction equilibrium.
Air Standard Cycles: Carnot, Otto, Diesel, Dual, Brayton cycles.
Vapor Cycles: Rankine cycle, reheat/regenerative cycles, vapor compression refrigeration cycles.
References: Sonntag, Borgnakke and Van Wylen, Nag, Wark, Moran and Shapiro, Rogers and Mayhew.

Extensive Properties: Depend on the mass e.g., volume, internal energy.
Intensive Properties: Independent of mass e.g., temperature, pressure.
Specific Values: Intensive properties derived per unit mass of extensive properties e.g., specific volume.

Specified by uniform and time-invariant properties.
Equilibrium states: No interaction with surroundings or internal processes cease.
Gibbs Phase Rule: Determines number of independent intensive properties needed to specify the state.

Thermodynamic Equilibrium: Uniform and invariant properties, no internal or external processes.
Types of Equilibrium: Thermal, mechanical, and chemical equilibrium.
Dead State: Properties same as surroundings.

Thermodynamic processes, types of equilibrium, concept of temperature, energy transfer.