Course detail

Thermomechanics

FSI-6TT-KAcad. year: 2024/2025

The course is concerned with the following topics: Basic quantities of state. Equation of state of an ideal gas. Mixtures of ideal gases. The First Law of Thermodynamics - heat, work, internal energy, enthalpy. The Second Law of thermodynamics, entropy. Reversible and irreversible processes of gases. The thermodynamics of vapours. Vapour tables and diagrams. The Clausius-Clapeyron Equation. Thermodynamic processes in vapours. Combustion of fuels. Calorific value, heat of combustion. Stoichiometric combustion equations. Stoichiometric ratio, excess air coefficient.  Thermodynamics of moist air. Definitive quantities, tables, diagram. Isobaric processes of moist air, evaporation from a free surface. Thermodynamics of flow of gases and vapors. Adiabatic flow through nozzles. The cycles of heat gas and heat steam engines. Compressors. The cycles of cooling devices and heat pumps. Fundamentals of heat transfer. Stationary heat conduction. Heat transfer by convection, similarity theory. Overall heat transfer, heat exchangers. Heat transfer by radiation. Radiation between surfaces.

Language of instruction

Czech

Number of ECTS credits

6

Mode of study

Not applicable.

Guarantor

prof. Ing. Josef Štětina, Ph.D.

Department

Energy Institute (EÚ)

Entry knowledge

Knowledge of mathematics and physics.

Rules for evaluation and completion of the course

A written examination that includes tests using computers. The emphasis is on theory and solving practical examples. Depending on the result of the written part of the exam, the exam may also include an oral part verifying knowledge from the written part of the exam. The overall assessment includes a 30 % assessment of the exercises.

 

Controlled attendance at exercises, in case of excused absence calculation of substitute examples. Knowledge of the exercises is verified by preparing projects and a test based on the calculation of examples. With the possibility of one correction.

Aims

The course objective is for students to acquire competency to carry out technical computation in the area of thermodynamics and heat transfer. Students will apply theoretical knowledge to machinery and technological fields.


Students will acquire skills to carry out technical computation in the area of thermodynamics and heat transfer: Computation of heat engines and cooling systems. Heat balance of material and machine systems, in gases, vapors, buildings and technological processes.

Study aids

Not applicable.

Prerequisites and corequisites

Not applicable.

Basic literature

Incropera F.P., DeWitt D.P.: Fundamentals of Heat and Mass Transfer
Pavelek M. a kol.: Termomechanika
Sazima M. a kol.: Sdílení tepla
Sazima M. a kol.: Teplo

Recommended reading

Gengel Y.A., Boles M.A.: Thermodynamics in engineering approach
Hloušek J. a kol.: Termomechanika, , 0
Kavička F.: Termokinetika tuhn. (sb.př.), , 0
Kavička F.: Termokinetika tuhnutí, , 0

Classification of course in study plans

  • Programme B-STR-K Bachelor's

    specialization SSZ , 2 year of study, summer semester, compulsory

Type of course unit

 

Guided consultation in combined form of studies

22 hod., compulsory

Teacher / Lecturer

prof. Ing. Josef Štětina, Ph.D.

Syllabus

  1. Basic terms. Basic laws and equations of state for an ideal gas. Heat capacity.
  2. Mixtures of ideal gases, Dalton’s Law, equations of state for mixtures and their components.
  3. The First Law of Thermodynamics and its two mathematical forms. Heat, volume and technical work, internal energy, enthalpy. The First Law of Thermodynamics for an open system and its equations.
  4. Reversible processes in ideal gases, changes of quantities of state, heat calculation, calculations of internal energy, enthalpy, of volume and technical work, p-v diagrams.
    Heat cycles, thermal efficiency, work. The Carnot cycle. The Second Law of Thermodynamics, entropy and general equations for entropy changes. Reversible processes and the Carnot cycle in a T-s diagram. The reversed and irreversible Carnot cycle. Irreversible processes in technical practice.
  5. The cycles of heat steam engines. Combustion engines, gas turbines.
  6. Van der Waals equations of state for real gases. The thermodynamics of vapour, p-v, T-s and h-s diagrams and vapour tables. The Clausius-Clapeyron Equation. Thermodynamic processes in vapours, changes in quantities of state, heat calculation, calculations of internal energy, enthalpy, of volume and technical work.
  7. The cycles of heat steam engines. The Rankin-Clausius cycle. The cycles of cooling devices and heat pumps. Combustion of fuels. Calorific value, heat of combustion. Stoichiometric combustion equations. Stoichiometric ratio, excess air coefficient.
  8. Thermodynamics of humid/atmospheric air. The definition of humidity and enthalpy of humid air, the enthalpy-relative humidity diagram. Cooling, heating, mixing and increasing the humidity of air, adiabatic evaporation from a free surface. Psychrometers.
  9. Continuity and Bernoulli’s equations. The Prandtl tube, the speed of sound, the Mach number. Isentropic flow of an ideal gas and steam through a narrowing opening and the Laval nozzle and their calculation. The Laval nozzle with various input conditions and the effect of back pressure. Reaction engines
  10. Heat transfer by conduction. 3D differential equations for stationary and transient heat conduction with an internal source using Cartesian and cylindrical coordinates. Heat and temperature conductivity. Stationary heat conduction through a planar and cylindrical single- and multiple-layer wall.
  11. Heat transfer by convection. The 3D Fourier-Kirchoff’s equation, The Navier-Stokes equation, boundary conditions. The Similarity Theory in heat convection. Derivation of the criteria of similarity. Criterion equations for natural and forced convection.
  12. Stationary overall heat transfer through a planar or cylindrical single- or multiple-layer wall. Heat exchangers, the mean temperature logarithmic gradient, algorithms for calculation.
  13. Heat transfer by radiation. The basic laws (Kirchhoff’s First and Second Law, Planck’s Law, the Stefan-Boltzman Law, Wien’s Law). Radiation between two parallel walls and between mutually surrounding surfaces.

Guided consultation

43 hod., optionally

Teacher / Lecturer

prof. Ing. Josef Štětina, Ph.D.

Syllabus

Calculations:

  1. State quantities of ideal gas and ideal gas mixture. Calorimetric balance calculations.
  2. Reversible changes of ideal gas - state variables, heat, work, internal energy changes, entropy.
  3. Carnot cycle, thermal efficiency, entropy changes. I. Open system law (control volume method)
  4. Compressors Cycles of internal combustion engines and gas turbines.
  5. Thermodynamic processes in vapours - state variables, heat, work, internal energy changes, entropy.
  6. Rankine-Clausius cycle, thermal power plant cycles including nuclear.
  7. Basic parameters of moist air and its treatment (heating, cooling, mixing, humidification).
  8. Adiabatic flow through a tapered orifice or Laval nozzle. Design of its main dimensions.
  9. Cycles of combustion turbines, jet and rocket engines.
  10. Stationary heat conduction through planar and cylindrical walls, single or compound. Stationary heat transfer - heat transfer coefficient, heat flux
  11. Heat transfer coefficient by convection and heat flux by convection.
  12. Basic calculation of a heat exchanger. Radiation between surrounding surfaces.
  13. Credit test