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  2. Heat flux - Wikipedia

    en.wikipedia.org/wiki/Heat_flux

    In physics and engineering, heat flux or thermal flux, sometimes also referred to as heat flux density [1], heat-flow density or heat-flow rate intensity, is a flow of energy per unit area per unit time. Its SI units are watts per square metre (W/m 2). It has both a direction and a magnitude, and so it is a vector quantity.

  3. Heat transfer coefficient - Wikipedia

    en.wikipedia.org/wiki/Heat_transfer_coefficient

    However, one needs to select if the heat flux is based on the pipe inner or the outer diameter. If the heat flux is based on the inner diameter of the pipe, and if the pipe wall is thin compared to this diameter, the curvature of the wall has a negligible effect on heat transfer. In this case, the pipe wall can be approximated as a flat plane ...

  4. R-value (insulation) - Wikipedia

    en.wikipedia.org/wiki/R-value_(insulation)

    R-value is the temperature difference per unit of heat flux needed to sustain one unit of heat flux between the warmer surface and colder surface of a barrier under steady-state conditions. The measure is therefore equally relevant for lowering energy bills for heating in the winter, for cooling in the summer, and for general comfort.

  5. Heat transfer - Wikipedia

    en.wikipedia.org/wiki/Heat_transfer

    A heat engine is a system that performs the conversion of a flow of thermal energy (heat) to mechanical energy to perform mechanical work. [32] [33] A thermocouple is a temperature-measuring device and a widely used type of temperature sensor for measurement and control, and can also be used to convert heat into electric power.

  6. Conjugate convective heat transfer - Wikipedia

    en.wikipedia.org/wiki/Conjugate_Convective_Heat...

    The contemporary conjugate convective heat transfer model was developed after computers came into wide use in order to substitute the empirical relation of proportionality of heat flux to temperature difference with heat transfer coefficient which was the only tool in theoretical heat convection since the times of Newton. This model, based on a ...

  7. Thermoelectric effect - Wikipedia

    en.wikipedia.org/wiki/Thermoelectric_effect

    The thermoelectric effect is the direct conversion of temperature differences to electric voltage and vice versa via a thermocouple. [1] A thermoelectric device creates a voltage when there is a different temperature on each side. Conversely, when a voltage is applied to it, heat is transferred from one side to the other, creating a temperature ...

  8. Newton's law of cooling - Wikipedia

    en.wikipedia.org/wiki/Newton's_law_of_cooling

    is the heat flux transferred out of the body (SI unit: watt/m 2), is the heat transfer coefficient (assumed independent of T and averaged over the surface) (SI unit: W/(m 2 ⋅K)), is the temperature of the object's surface (SI unit: K),

  9. Heat transfer physics - Wikipedia

    en.wikipedia.org/wiki/Heat_transfer_physics

    The macroscopic energy equation for infinitesimal volume used in heat transfer analysis is [6] = +, ˙, where q is heat flux vector, −ρc p (∂T/∂t) is temporal change of internal energy (ρ is density, c p is specific heat capacity at constant pressure, T is temperature and t is time), and ˙ is the energy conversion to and from thermal ...