Oil Streak Visualisation of Fluid Flow Over Single D-Type Cylinder

Astu Pudjanarsa, Herman Sasongko

Department of Mechanical Engineering, Faculty of Industrial Technology, Sepuluh Nopember Institute of Technology, Kampus Keputih-Sukolilo Surabaya, Indonesia.

DOI: 10.4236/wjm.2012.24024                

Abstract

An experimental study on the effect of cut angle on circular cylinders to the drag force is performed. Six cylinders were cut at different angles and the air flow impinges perpendicular to the cut surface of the cylinder. The cut angles applied include: 0°, 30°, 45°, 53°, 55°, and 75°. The shear layer visualisation on the surface of cylinder was conducted as well. Drag force was measured using a wind tunnel force balance and the wind speed was set so that a corresponding Rey-nolds number of 5.3 × 10⁴ was achieved. Visualisation was carried out by covering the cylinder with paper wetted by mixture of oil and titanium dioxide powder. Experimental results show that drag force has similar trend to that of previous experiment results. The minimum drag coefficient is attained at the cut angle of 53°. From oil streak visualisation the streamlines pattern of the flow over the cylinder could be reconstructed.

Keywords

Cut Angle; Drag Force; Visualisation; Streamline

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	A. Roshko, “On the Drag and the Wake of Bluff Bodies,” Journal of Aeronautical Science, Vol. 22, 1955, pp. 124132.
[2]	R. W. Fox, A. T. McDonald and P. J. Pritchard, “Introduction to Fluid Mechanics,” 6th Edition, Chapter 9, John Wiley and Sons, Inc., New York, 2004, pp. 409-466.
[3]	S. Aiba, “Fluid Dynamic Drag of an Axially Symmetrical Bluff Body Consisting of a Plane Surface and Spherical Surface,” Journal of Fluids Engineering, Vol. 120, No. 4, 1998, pp. 851-853. doi:10.1115/1.2820750
[4]	N. Adityawarman, “Experimental Study on the Effect of Variation Cutting Angles on Spheres to the Drag,” Bachelor Final Project, Department of Mechanical Engineering, Sepuluh Nopember Institute of Technology, Surabaya, 2000.
[5]	A. Pudjanarsa, “Experimental Study on the Effect of Turning Angle on Drag and Lift Forces for Various Cut Angles on Spheres,” Journal of Mechanical Engineering Science, Vol. 221, No. 3, 2007, pp. 303-306. doi:10.1243/0954406JMES412
[6]	S. Aiba and H. Watanabe, “Flow Characteristics of a Bluff Body Cut from a Circular Cylinder,” Journal of Fluids Engineering, Vol. 119, No. 2, 1997, pp. 453-454. doi:10.1115/1.2819155
[7]	I. Andriyono, “Experimental Study on the Effect of Cut Angle on Cylinder to the Drag Force,” Bachelor Final Project, Department of Mechanical Engineering, Sepuluh Nopember Institute of Technology, Surabaya, 1999.
[8]	R. Efendi, “Experimental Study on the Characteristic of Fluid Flow over D Type Single Cylinder,” Bachelor Final Project, Department of Mechanical Engineering, Sepuluh Nopember Institute of Technology, Surabaya, 2007.
[9]	Y. Triyogi, D. Suprayogi and E. Spirda, “Reducing the Drag on Circular Cylinder by Upstream Installation of an I-Type Bluff Body as Passive Control,” Journal of Mechanical Engineering Science, Vol. 223, No. 10, 2009, pp. 2291-2295. doi:10.1243/09544062JMES1543