Effects of upstream sharp edge square and diamond cylinders on the FIV of a circular cylinder

The overall transverse response of a circular cylinder in the wake of a sharp edge cylinder look like a VIV type of response. The ever increasing type of transverse oscillations for tandem circular cylinders at low spacing ratios no longer exists. It is concluded that in general, the wake from the upstream sharp edge cylinder has mitigated (around 40%) the lift force coefficient on the downstream cylinder. The oscillations and pressure frequencies occur primarily at the upstream sharp edge cylinder shedding frequency. It appears that the upstream wake is much stronger than the vortices past the downstream cylinder, so they take control of the downstream circular cylinder oscillations and shedding.