Thermal resistance 23 of multi-layer backfill method

Thermal resistance offered by the material in layer 3 along the flow path q2.

Symbol
$R_{q23}$
Unit
K.m/W
Formulae
$\frac{\ln{\left(\frac{2 \left(C_{2} \left(- s_{T} + \operatorname{Max}{\left(a_{T},b_{T} \right)}\right) + s_{T}\right)}{D_{o}} \right)}}{k_{3} \left(\operatorname{atan}{\left(\frac{a_{T}}{s_{T}} \right)} + \operatorname{atan}{\left(\frac{b_{T}}{s_{T}} \right)}\right)}$
$D_{o}$