Course detail

Thermomechanics

FSI-6TT Acad. year: 2024/2025 Summer semester

Supervisor

prof. Ing. Josef Štětina, Ph.D.

Department

Energy Institute

Learning outcomes of the course unit

Prerequisites

Planned learning activities and teaching methods

Assesment methods and criteria linked to learning outcomes

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.

Language of instruction

Czech

Aims

Specification of controlled education, way of implementation and compensation for absences

The study programmes with the given course

Programme B-MAI-P: Mathematical Engineering, Bachelor's
branch ---: no specialisation, 6 credits, compulsory

Programme C-AKR-P: , Lifelong learning
branch CLS: , 6 credits, elective

Programme B-STR-P: Engineering, Bachelor's
branch KSB: Quality, Reliability and Safety, 6 credits, compulsory

Programme B-STR-P: Engineering, Bachelor's
branch SSZ: Machine and Equipment Construction, 6 credits, compulsory

Type of course unit

 

Lecture

39 hours, optionally

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.

Exercise

26 hours, compulsory

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