Artificial denticle-covered textures in Taylor-Couette flows

Riblet-textured surfaces, inspired by ribs on the denticles of sharks, have been demonstrated as an effective method to reduce the frictional drag force exerted on the wall. The response of these 2D grooves vary depending on their cross-sectional geometry, with previous research largely focused on V-grooves. However, shark denticles protrude outwards at an angle from the plane of the skin and overlap with the neighbors. In this talk, we investigate how the addition of this protrusion defined as an offset angle with respect to the base surface impacts the flow. We present the results of our experiments performed in a Taylor-Couette cell with textured 3D-printed inner rotors. Texture of each rotor consists of V-groove riblets broken up into separate denticles placed at an offset angle to the circumference of the base rotor. To achieve this design in a cylindrical coordinate system, the riblets are set to protrude from the rotor along the path of a logarithmic spiral. We will show our torque and velocity measurements in Couette flow and Taylor vortex flow regimes as a function of the Reynolds number and the geometry of the artificial denticles, and ultimately compare the results across the denticle-covered rotors and with base rotors with circumferential V-groove textures.