☀️ Thermal Radiation & Stefan-Boltzmann Law
Radiant Heat Transfer & Stefan-Boltzmann Calculator
Compute net radiative heat exchange ($q = \epsilon \sigma A (T_1^4 - T_2^4)$), radiative heat flux ($W/m^2$), and linearized radiation heat transfer coefficient ($h_r$).
🖤 Matte Black ($\epsilon = 0.98$)
👤 Human Skin ($\epsilon = 0.98$)
✨ Polished Aluminum ($\epsilon = 0.04$)
🪟 Glass ($\epsilon = 0.94$)
🧱 Brick ($\epsilon = 0.90$)
Radiation Inputs
m² (Human body ≈ 1.8 m²)
Net Radiant Heat Loss (q)
148.6 Watts
Net Flux ($q''$)
82.55 W/m²
Linearized $h_r$
5.90 W/m²·K
Blackbody Emitted
899.8 W
💡 Stefan-Boltzmann Radiation Formula:
$$q = 0.95 \times (5.67 \times 10^{-8}) \times 1.8 \times (307.15^4 - 293.15^4) = 148.6\text{ Watts}$$
Principles of Radiant Heat Transfer
All matter above absolute zero ($0\text{ K}$) emits electromagnetic radiation governed by the Stefan-Boltzmann law:
- Stefan-Boltzmann Constant ($\sigma$): $\sigma = 5.670374419 \times 10^{-8}\text{ W}/(\text{m}^2\cdot\text{K}^4)$.
- Net Radiative Heat Exchange: $$q = \epsilon \sigma A \left(T_1^4 - T_2^4\right)$$
- Linearized Heat Transfer Coefficient ($h_r$): $$h_r = \epsilon \sigma (T_1 + T_2)(T_1^2 + T_2^2) \implies q = h_r A (T_1 - T_2)$$