Author(s): Abhinav Thakurta; Ram Balachandar
Linked Author(s): Ram Balachandar
Keywords: No Keywords
Abstract: Helical strakes have been suggested for use as a passive method of control to prevent the occurrence of vortex shedding from circular wall mounted cylinders. The present study experimentally investigates the complex wake flow patterns behind a wall-mounted helical straked cylinder using particle image velocimetry (PIV) in a shallow flow. The paper compares the mean velocities, Reynolds stresses and wake structures of a plain cylinder with that of helical straked cylinders. The strakes’ configuration consists of three-start helical strakes with pitch (p) equal to 10d and a height (h) of 0.2d, where d is the diameter of the plain cylinder. The preliminary results show that the presence of helical strakes drastically changes the wake characteristics, which can influence not only the drag but also alter the flow structures. This can have important implications in reducing scour behind bridge piers.
Year: 2024