円弧型溝付回転円柱まわりの流動特性(G05-1 物体周りの流れ,G05 流体工学部門一般講演)

Abstract

The drag and lift coefficient characteristics of rotating cylinder with arc grooves is investigated. The circular cylinders with grooves have thirty-two arc grooves of different depth on the cylinder surface. Pressure of the cylinder surface is measured with the Reynolds number Re= (0.4-1.8) ×105, and rotation of 0-4500rpm.The drag and lift coefficients are calculated from pressure distribution. At Re=0.4×105, the drag coefficient CD of smooth cylinder is constant until the spin rate ratio α (α=rotating speed/uniform flow) =0.6, and CD decreases afterwards at 0.6 1.0×105.As groove depth becomes deep, CD becomes constant value as α increase. The lift coefficient CL of smooth cylinder increases as a increase.However, CL decreases to the minimum value as α further increase and CL increases again with the increase of α, CL indicated negative lift in Re>1.0×105.CL of cylinder with grooves become monotonous increases tendency in Re>1.0×105.As groove depth becomes deep, the increasing gradient of CL becomes small.