OHTC of partially buried pipe

The overall heat transfer coefficient (OHTC) of partially buried pipes is commonly modeled as an average, weighted on the exposed wetted surface area of the pipe.

Case when |$D_{ext}/2|>=H$.

Symbol
$U_{partially}$
Unit
W/(K.m$^2$)
Formulae
$\frac{U_{exposed} \beta_{b}}{\pi} + U_{ground} \left(- \frac{\beta_{b}}{\pi} + 1\right)$
Used in
$U_{OHTC}$