Lewis number
The Lewis number is a dimensionless similarity parameter to describe heat and mass transport. Learn more about it in this article.
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Calculation of the Nusselt numbers for forced flows over plates and in pipes
In this article you will find formulas for calculating the local and average Nusselt numbers for forced flows over plates and in pipes with circular cross sections.
Heat transfer coefficient for thermal convection
The heat transfer coefficient describes the convective heat transfer from a solid to a flowing fluid and vice versa! Learn more about it in this article.
Hydrodynamic boundary layer
The hydrodynamic boundary layer of a flow has a decisive influence on heat and mass transport. Learn more about it in this article.
Nusselt number to describe convective heat transfer
The Nusselt number is a dimensionless similarity parameter to describe convective heat transfer, independent of the size of the system. Learn more about it in this article.
Temperature profiles and heat flows through different geometries
In this article we discuss temperature curves and heat flows through a plane wall, through a cylindrical pipe and through a hollow sphere.
Thermal conduction in solids and ideal gases
The thermal conductivity in crystalline, non-metallic solids first increases and then decreases again with increasing temperature. Learn more about this behavior in this article.
Laser-Flash method for determining thermal conductivity (LFA)
With the Laser-Flash method (Laser Flash Analyser, LFA), the thermal conductivity is determined by the temperature rise in a test sample that is heated by a short laser pulse...
Transient-Hot-Wire method method for determining thermal conductivity (THW)
With the Transient-Hot-Wire method (THW), the thermal conductivity is determined by the change in temperature over time at a certain distance from a heating wire. Learn more about the...
Heat-Flow-Meter method for determining thermal conductivity (HFM)
With the Heat-Flow-Meter method (HFM) the thermal conductivity is determined by comparative measurement of the heat flow using a reference sample. Learn more about this absolute measurement method in...
Guarded-Hot-Plate method for determining thermal conductivity (GHP)
With the Guarded-Hot-Plate method (GHP) the thermal conductivity is determined by the electrical power output of a hot plate with guided heat conduction. Learn more about this measurement method...
Derivation of heat equation (diffusion equation)
The heat equation describes the temporal and spatial behavior of temperature for heat transport by thermal conduction. Read more about it in this article.
Thermal conductivity of gases
The thermal conductivity of ideal gases is not dependent on pressure for gases that are not too strongly diluted. This is no longer the case for gases with low...
Experimental setup for determining thermal conductivity
In this article you can learn more about the experimental determination of the thermal conductivity of materials using steam and ice.
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Heat transfer by thermal radiation
With thermal radiation, heat is transferred by electromagnetic waves without the presence of a substance! You can read more about this mechanism in this article.
Heat transfer by thermal convection
With heat transfer by thermal convection, heat is transported with a flowing substance. Convection only occurs in fluids, i.e. gases and liquids. You will find more information in this...
Heat transfer by thermal conduction
Heat transfer by thermal conduction means that heat is conducted through a material. Heat energy is transferred from molecule to molecule at the atomic level. More information on this...
Rate of heat flow: Definition and direction
The rate of heat flow refers to the heat energy transferred per unit of time ("heat output"). The drive for the heat flow is a temperature difference. Learn more...
Thermal conductivity (Fourier’s law)
Thermal conductivity is a measure of how well or poorly a material conducts heat energy (measure of the strength of heat conduction)! You can read more about this in...
Heat and thermodynamic equilibrium
In thermodynamics, heat is the transport of energy due to a temperature difference. Heat in this respect is never "contained" in an object! Learn more about the thermodynamic concept...
Heat transfer (heat transport)
Heat transfer is the transport of thermal energy from a warmer object to a cooler object. A distinction is made between thermal convection, thermal conduction and thermal radiation. You...
