Mixed Convection

When a surface is subjected to external flow, the problem involves both natural and forced convection. The relative importance of each mode of heat transfer is determined by the value of the coefficient Gr/Re\(^2\):

  • If \(\text{Gr}/\text{Re}^2 \ll 1\), flow is primarily by forced convection.

  • If \(\text{Gr/Re}^2 \gg 1\), free convection becomes dominant.

  • If \(\text{Gr/Re}^2 \approx 1\), mixed convection.