Apportioning factor duct

Factor for apportioning the thermal capacitance of a duct

Symbol
$p_{d}$
Formulas
$\frac{1}{2\ln\left(\frac{Do_{d}}{Di_{d}}\right)}-\frac{1}{\left(\frac{Do_{d}}{Di_{d}}\right)^2-1}$
Related
$Di_{d}$
$Do_{d}$