\large
$$
HL_{SedLaunderEst}  = \left( {0 + {8 \over {g\pi ^2 }}{{L_{SedLaunderEst} Q_{Sed} ^2 } \over {ND_{SedLaunderEst} ^5 }}} \right)\left( {{1 \over 3} + {1 \over {2N_{SedLaunderOrifices} }} + {1 \over {6N_{SedLaunderOrifices} ^2 }}} \right)
$$