Thermal conductivity

Thermal Conductivity

Thermal conductivity is a property of matter that describes its ability to conduct heat. It is denoted by the symbol k or λ. In the International System of Units (SI), thermal conductivity is measured in watts per meter-kelvin (W/(m·K)).

Definition

Thermal conductivity is defined as the quantity of heat, Q, transmitted through a thickness, L, in a direction normal to a surface of area, A, due to a temperature gradient, ΔT, under steady state conditions and when the heat transfer is dependent only on the temperature gradient.

Determination

Thermal conductivity is usually determined by the Fourier's Law for heat conduction. The law states that the time rate of heat transfer through a material is proportional to the negative gradient in the temperature and the area, at right angles to that gradient, through which the heat flows.

Factors Affecting Thermal Conductivity

Several factors can affect the thermal conductivity of a material. These include the material's phase (whether it is solid, liquid, or gas), its temperature, its density, and its molecular bonding.

Applications

Thermal conductivity is an important property in many practical applications, including the design of heat exchangers, heat sinks, and insulation materials.

See Also

• Heat Transfer
• Thermal Diffusivity
• Thermal Resistance
• Thermal Conductivity Detector

References

Thermal conductivity Resources
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