Heat Transfer Mechanisms

Heat transfer occurs through three main mechanisms: conduction, convection, and radiation. Each mechanism follows distinct physical principles and equations.

Conduction

Heat transfer through direct contact between particles

q=−kAdTdxq = -k A \frac{dT}{dx}

Where:

  • q = heat transfer rate
  • k = thermal conductivity
  • A = cross-sectional area
  • dT/dx = temperature gradient

Convection

Heat transfer through fluid motion

q=hA(Ts−T∞)q = h A (T_s - T_\infty)

Where:

  • h = convection heat transfer coefficient
  • Ts = surface temperature
  • T∞ = fluid temperature

Radiation

Heat transfer through electromagnetic waves

q=ϵσA(T14−T24)q = \epsilon \sigma A (T_1^4 - T_2^4)

Where:

  • ε = emissivity
  • σ = Stefan-Boltzmann constant
  • T = absolute temperature