Drag Reduction Effect of 3D-Printed Riblets with Various Shapes in Turbulent Taylor-Couette Flow

Abstract

Drag reduction effect of riblet in turbulent Taylor-Couette flow is experimentally investigated. A motor and a torque meter are installed at the top of the cylinders to investigate the effect of drag reduction by torque measurement. The outer cylinder is fixed and the inner cylinder rotates on its cylindrical axis. Two inner cylinders manufactured by 3D printer, one with a flat surface and the other with sinusoidal riblet, were compared to investigate the drag reduction effect. As a result of torque measurement, it was confirmed that the drag increased about 20% at maximum by sinusoidal riblet. In order to achieve high drag reduction effect, it is necessary to investigate riblet that focuses on Taylor vortex in addition to turbulent components.