Full perturbation solution for the flow in a rotated torus

We present a perturbation solution for a pressure-driven fluid flow in a rotating toroidal channel. The analysis shows the difference between the solutions of full and simplified equations studied earlier. The result is found to be reliable for {\it low} Reynolds number ($\mathbb{R}$) as was the case for a previously studied solution for high $\mathbb{R}$. The convergence conditions are defined for the whole range of governing parameters. The viscous flow exhibits some interesting features in flow pattern and hydrodynamic characteristics.