  In this paper, the strong formulation of the generalised Navier-Stokes
momentum equation is investigated. Specifically, the formulation of
shear-stress divergence is investigated, due to its effect on the performance
and accuracy of computational methods. It is found that the term may be
expressed in two different ways. While the first formulation is commonly used,
the alternative derivation is found to be potentially more convenient for
direct numerical manipulation. The alternative formulation relocates a part of
strain information under the variable-coefficient Laplacian operator, thus
making future computational schemes potentially simpler with larger time-step
sizes.
