Laminar Flow in Pipe
[latex size="2"]Q=\frac{\pi D^4\Delta p}{128\mu L}[/latex]
where, $latex Q$ is flow rate, $latex D$ is the inner diameter of the pipe, $latex \Delta p$ is the pressure drop, $latex \mu$ is viscosity, $latex L$ is pipe length.
Laminar flow between eccentric cylinders
[latex size="2"]Q=\frac{\pi Dh^3\Delta p}{12\mu L}(1+1.5\varepsilon)\pm\frac{\pi Dhu_0}{2}[/latex]
where, $latex \varepsilon=e/h$ is the eccentricity ratio, $latex e$ is center distance, $latex h$ is the clearance when the two cylinders are co-axial, $latex u_0$ is the relative motion velocity between two cylinders.