Mean Kinetic Energy in Arrays of Undulated Cylinders

Extensive studies of fluid flow over basic cylinders have limited the complex three-dimensional undulated topographies of seal whiskers (vibrissae) to biological studies and single cylinder experiments or simulations. The present study experimentally investigates the momentum deficit, and its interactions, between nine undulated elliptic cylinders with various streamwise spacings and spanwise staggering. Mean kinetic energy budgets are calculated for various configurations and axial locations. The undulated specimens were 3D printed using high-resolution fused deposition modelling (FDM) and were smoothed and painted afterwards. The cylinders were scaled to a mean chord length (C) of 3.36 cm, a mean thickness of 1.75 cm, and a total length (L) of 60 cm. The array was mounted onto a grid with 1C spacing in the Portland State University wind tunnel measuring 5 m long, 1.2 m wide, and 0.8 m high. Flow visualization behind the array was performed using 2D-3C Stereo Particle Image Velocimetry (SPIV). Measurements were taken at increments of five streamwise chord lengths (C) with a Reynolds number ranging between 13,000 to 23,000. To study downstream development, ensemble averages were generated using 2,000 images per each of two imaging planes. The bio-inspired engineering model has broad applications in column structure designs that aim to minimize momentum deficits and diminish vibrational response, chemical mixing, biosensors, and behavioural biological research.