In this presentation I discuss how findings from closed form solutions to circular fluid motion can be used to draw inferences on bank erosion at bends. As straight line inertial water motion enters a bend, lateral changes in pressure steer the water around the bend. When Archimedes’ principle of mass displacement for equilibrium conditions is applied in the rotating reference frame, one finds that stream bank particles can move upward or downward depending on density stratification and displacement volume, with a tendency of displaced particles to move to the center line of the bend. Velocity distribution from convergent and divergent flows alters this interpretation. Solution of the angular momentum equation for torque due to external boundary conditions with equivalent rotational flow conditions for undrained shear vane testing of soils is compared. Results show that straight line velocities typically assumed for soil failure differs considerably from velocities at bends.
