Fundamentals of thermodynamics
Thermodynamics describes the general theory of energy and substance conversion. The fundamentals of thermodynamics deal with the behaviour of systems during temperature changes.
Thermodynamics
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The thermodynamic state variables describe the measurable properties of a system. Any thermal equilibrium state can be unambiguously described by means of state variables.
Thermodynamic state variables
Experimental introduction to temperature measurement: methods, areas of application, characteristics
Learning objectives/experiments
- learning the fundamentals of temperature measurement by experimentation
- familiarisation with the various methods, their areas of application and special features
- non-electrical methods: gas- and liquid-filled thermometers, bimetallic thermometers and temperature measuring strips
- electrical methods: thermocouple, resistance thermometer Pt100, thermistor (NTC)
- determining air humidity with a psychrometer
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Investigation of transient temperature behaviour and defined temperature jumps
Learning objectives/experiments
- familiarisation with different temperature measurement methods:
- non-electrical methods: liquid thermometer, bimetal thermometer
- electrical methods: thermocouple type K, Pt100 resistance thermometer, NTC thermistor
- determination of air humidity with a psychrometer
- familiarisation with the function of the individual temperature measuring instruments
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Measurement of positive and negative pressure with different measuring devices
Learning objectives/experiments
- familiarisation with 2 different measuring methods:
- direct method with U-tube manometer and inclined tube manometer
- indirect method with Bourdon tube pressure gauge
- principle of a Bourdon tube pressure gauge
- calibrating mechanical manometers
Climatic chamber with adjustable humidity; comparison of four measuring methods
Learning objectives/experiments
- measuring methods for air humidity measurement
- psychrometric humidity measurement
- hygrometric humidity measurement
- capacitive humidity measurement
- characteristic variables to describe air humidity
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Isothermal and isochoric change of state of air
Learning objectives/experiments
- demonstrating the laws of state changes in gases experimentally
- isothermal change of state, Boyle-Mariotte law
- isochoric change of state, Gay-Lussac’s 2nd law
Determination of the adiabatic exponent according to Clément-Desormes
Learning objectives/experiments
- determination of the adiabatic exponent according to Clément-Desormes
- adiabatic change of state of air
- isochoric change of state of air
Heat transfer takes place in two fundamentally different ways. A distinction is made thereby between material-bound (convection and heat conduction) and non-material bound (radiation).
Heat transport
Investigation of the thermal conductivity of different metals
Learning objectives/experiments
- time dependency until the steady state is reached
- calculate the thermal conductivity λ of different metals
- calculate the thermal resistance of the specimen
- heat transfer with different specimens connected in series
- effect of specimen length on heat transfer
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Determination of the coefficient of thermal conductivity for gaseous and liquid fluids
Learning objectives/experiments
- steady heat conduction in gases and liquids:
- determine the thermal resistance of fluids
- determination of thermal conductivities λ for different fluids at different temperatures
- transient heat conduction in fluids:
- interpret transient states during heating and cooling
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Investigation of heat conduction and convection using the example of a cooling fin
Learning objectives/experiments
- effect of heat conduction and convection on heat transfer
- effect of free and forced convection on heat transfer
- calculate convective heat transfers
- effect of different materials on heat conduction
- effect of specimen length on heat transfer
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Calculation of convective heat transfer at different geometries: flat plate, cylinder, tube bundle
Learning objectives/experiments
- free and forced convection
- calculation of convective heat transfer at different geometries
- flat plate
- cylinder
- tube bundle
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Effect of different surfaces on heat transfer
Learning objectives/experiments
- verify Lambert’s inverse-square law
- verify Stefan-Boltzmann law
- verify Kirchhoff’s law
- study transient behaviour
- create power balances
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Investigation of thermal and light radiation; thermal radiator and thermopile for the investigation of thermal radiation
Learning objectives/experiments
- Lambert’s direction law
- Lambert’s distance law
- Stefan-Boltzmann law
- Kirchhoff’s laws
Study of heat conduction in solids
Learning objectives/experiments
- linear heat conduction (plane wall)
- determination of temperature profiles for different materials
- determination of the temperature profile in case of a disturbance
- determination of the thermal conductivity λ
- radial heat conduction
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Investigation of the insulation properties of typical materials from the building materials sector
Learning objectives/experiments
- determine the thermal conductivity λ of different materials
- determine the thermal resistance
- thermal conductivity λ for several samples connected in series (up to a thickness of 50mm)
Linear heat conduction in metals; non-steady state temperature distribution
Learning objectives/experiments
- steady heat conduction
- transient heat conduction
- temperature/time profiles
- calculate thermal conductivity λ of different metals
Heat transport between heating element and vessel wall by convection and radiation
Learning objectives/experiments
- experiments in vacuum
- heat transfer by radiation
- determination of the radiation coefficient
- experiments at ambient pressure or positive gauge pressure
- heat transfer by convection and radiation
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A gaseous, liquid or solid state is called phase. Phase transition is the change from one phase to another.
Phase transition
Pressure and temperature measurement in a steam boiler
Learning objectives/experiments
- recording the vapour pressure curve of water
- presentation of the relationship between pressure and temperature in a closed system
- temperature and pressure measurement
Pressure and temperature measurement in a steam boiler, software-supported experiments and evaluation
Learning objectives/experiments
- recording the vapour pressure curve of water
- presentation of the relationship between pressure and temperature in a closed system
- temperature and pressure measurement
- Marcet boiler experiment
Different forms of evaporation in an externally heated pipe
Learning objectives/experiments
- observation of typical forms of evaporation
- single phase liquid flow
- sub-cooled boiling
- slug flow
- annular flow
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Visualisation of different forms of evaporation in a transparent pressure vessel
Learning objectives/experiments
- visualisation of different forms of evaporation
- free convection boiling
- nucleate boiling
- film boiling
- heat transfer
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Measurement of heat transfer in dropwise and film condensation
Learning objectives/experiments
- dropwise and film condensation
- determination of the heat transfer coefficient
- effect of pressure, temperature and non-condensable gases on the heat transfer coefficient
