Effect of Lip Angle on Wake Dynamics

Abstract

In this research Inverted-C shaped circular cylinders with four different cut angles were studied and compared to same cut cylinders with Lip angle. Particle Image Velocimetry (PIV) is used for this research (which is a non-intrusive technique) in a closed loop water channel with variable tunnel speed varying from 10 cm/s to 50 cm/s having turbulent intensity less than 7%. The study focused on change in wake characteristics when different cylinders were compared. Four cylinders cut at 45-deg, 90-deg, 135-deg and 180-deg were studied and compared with same cylinders with Lip angle of 70-deg. Diameter of cylinder was taken as 25 mm with thickness of 2.5 mm taken at Reynold’s Number as 2400. It was found that by adding lip angle in cut cylinders characteristics of wake were significantly altered. Cylinders with lip angle shown wake greater in size. Recirculation length also significantly improved. Maximum size of wake was found in Inverted-C shaped 135-deg cut circular cylinder with Lip angle. Moreover, it is extrapolated that by adding lip angle, 14% more energy can be harvested adopting this minor change in shape of circular cylinder.