\[\alpha=\frac{k}{\rho c_p}\]
Variables
alpha[α]thermal diffusivity (m²/s)
kthermal conductivity (W/m·K)
rho[ρ]density (kg/m³)
Cp[C_p]specific heat capacity at constant pressure (J/kg·K)
Description
What is this formula?
Thermal diffusivity measures how quickly heat propagates through a material. It combines the effects of thermal conductivity, density, and specific heat capacity into a single property that characterizes transient heat transfer behavior.
When to use it
Use this formula when analyzing heat penetration, transient conduction, thermal response times, and temperature distribution in solids subjected to changing thermal conditions.
Example
Given:
k = 205 W/m·K
rho = 2700 kg/m³
Cp = 900 J/kg·K
Formula:
α = k/(ρCp)
Substitution:
α = 205/(2700 × 900)
Result:
α = 8.44×10^-5 m²/s
Applications
Heat transfer analysis, transient conduction problems, thermal insulation studies, electronic cooling, materials engineering, furnace design, and thermal response modeling.