Thermodynamics

Mechanical Engineering
5.5 ECTS; 2º Ano, 1º Semestre, 30,0 T + 30,0 TP + 4,50 OT

Lecturer
- Diogo Gomes Almeida Chambel Lopes

Prerequisites
Not applicable.

Objectives
This course presents an initial approach of thermodynamics from the point of view of Mechanical Engineering. Case studies are used to address problems typically found by mechanical engineers in their profession.

Program
Chapter 1: Basic concepts and definitions.
1.1 Thermodynamic Systems
1.2 Macroscopic and microscopic points of view
1.3 Property, state, process and balance
1.3.1 Extensive and intensive properties
1.3.2 Phases and physical states of matter
1.4 Reversible and irreversible transformations
1.4.1 Irreversibilities
1.4.2 Reversibility
1.5 Thermodynamic Coordinates
1.5.1 Units for mass, length, time and force
1.5.2 Volume
1.5.3 Density and specific volume
1.5.4 Pressure
1.5.5 Temperature
1.5.6 Internal Energy
1.5.7 Enthalpy
1.5.8 Entropy
1.6 Zero Principle of thermodynamics
1.7 Methodology for solving thermodynamic problems
Chapter 2: Energy and Transfer Modes
2.1 Forms of Energy
2.2 Concepts of mechanical energy
2.2.1 Work and kinetic energy
2.2.2 Potential energy of position
2.3 Energy transfer by work
2.3.1 Convention of signs and notation
2.3.2 Work of expansion or compression
2.4 Energy transfer by heat
2.4.1 Convention of signs and notation
2.4.2 Heat Transfer Modes
2.4.3 Specific heat
2.5 Relationship between work and heat
2.6 First principle of Thermodynamics
2.6.1 Definition of energy variation
2.6.2 Energy balance for closed systems
2.6.3 Conservation of mass
2.7 Transformations and energy transfers
2.7.1 Transformations politrópicas
2.7.2 Hyperbolic Transformations
2.7.3 Transformations adiabatic and isentropic
2.7.4 Transformations isobaric
2.7.5 Transformations isochoric
2.7.6 Isothermal Transformations
Chapter 3: Fundamental Properties of gases
3.1 Composition of dry air and adopted standards
3.2 Law of Boyle and Mariotte
3.3 Law of Charles and Gay-Lussac
3.4 Equation characteristic of perfect gases
3.5 Joule's Law
3.6 Specific heats of gases
3.6.1 Specific heat at constant volume
3.6.2 Specific heat at constant pressure
3.6.3 Difference between the specific heats of a gas
3.7 Mixtures of gases
3.7.1 Dalton law of partial pressures
3.8 Variation of entropy of a perfect gas
3.9 Considerations about the types of transformations
3.9.1 Transformations politrópicas
3.9.2 Adiabatic transformations
3.9.3 Isothermal Transformations
Chapter 4: Properties of a pure substance
4.1 Pure Substance
4.2 Principle of State
4.2.1 Independent Properties of pure substances
4.3 phases of a pure substance
4.3.1 Important Considerations about the phase changes
4.3.2 Substances normal and abnormal
4.4 Tables of thermodynamic properties
4.5 Diagrams of thermodynamic properties
4.5.1 P-v diagram
4.5.2 P-T diagram
4.5.3 Surface p-v-T
4.5.4 T-s diagram
4.5.5 Other representations
Chapter 5: First principle of thermodynamics - control volumes
5.1 Conservation of mass and volume control
5.1.1 Volumetric and mass flow rates
5.2 Energy balance for a vc
5.2.1 Energy displacement
5.2.2 Total energy of a flowing fluid
5.3 Flow in steady
5.3.1 Characteristics of flow processes in continuous operation
5.3.2 Conservation of mass and energy
5.4 Some devices flow steady
5.4.1 Nozzles and diffusers
5.4.2 Turbines and Compressors
5.4.3 Throttle valves
5.4.4 Tanks Mixers
5.4.5 Heat exchangers
5.4.6 Flow in tubes and ducts
5.5 Process flow not permanent
5.5.1 Process flow in uniform regime
Chapter 6: Second Law of Thermodynamics
6.1 Introduction to the Second Law
6.2 Thermal Machines
6.2.1 Third Law of Thermodynamics
6.3 Refrigerators and Heat Pumps
6.3.1 Thermal Performance
6.3.2 Coefficient of performance, COP
6.4 Carnot Cycle
6.4.1 Principles of Carnot
6.4.2 Thermal Machine Carnot
Chapter 7: Steam power cycles
7.1 Assumptions for the standard air
7.2 Alternative Engines
7.3 Otto Cycle
7.4 Diesel Cycle
7.5 Mixed Cycle
7.6 Brayton cycle: the ideal cycle for gas turbines
7.6.1 Compressibility of gases - general
7.6.2 Cycle Power
7.7 Rankine Cycle
7.7.1 The ideal power cycle steam
7.7.2 Ideal Rankine Cycle
7.8 Stirling cycle and Ericsson

Evaluation Methodology
Final mark (FM)is calculated according to the following criteria:
Written test (T) - 60%
Lab work(Lab) - 40%
FM = 0.60. T + 0.40. Lab

Bibliography
- Cengel, Y. e Boles, M. (2012). Termodinâmica. NA: McGraw-Hill

Method of interaction
Tutorials including data-show. Practical exercises solved on the blackboard and laboratory experiments as needed.

Software used in class
N/A