Flow Fields in front of a Cylindrical Obstacle

Authors

  • Yulistiyanto B. Civil and Environmental Engineering Department, Faculty of Engineering, Gadjah Mada University, Yogyakarta

:

https://doi.org/10.9744/ced.12.2.79-91

Keywords:

cylindrical obstacle, experimental investigation, velocities distributions, vortex

Abstract

An experimental investigation, conducted in two different flows Reynolds number, was carried out to study the structure of the flow field upstream of a cylindrical obstacle. An Acoustic Doppler Velocity Profiler (ADVP) was used to obtain instantaneously the three directions of the mean velocity. Results of the experiments show the longitudinal velocities, , decrease approaching the cylinder, their distribution becomes more uniform and close to the bed a reverse flow is noticeable with increasing importance. The downward velocity component is clearly shown, continuing with the return flow near the bed, forming a vortex. At positions where the vortex appears upstream from the cylinder, a large increase of the three components of the turbulence intensities is remarked. Approaching the cylinder, one observes the shear stress decreases, having the opposite direction at positions close to the cylinder. A zero value of shear stress should be at the separation point.

References

Agui, J.H. and Andreopoulos, J., Experimental Investigation of a Three-Dimensional Boundary Layer Flow in the Vicinity of an Upright Wall Mounted Cylinder, J. Fluids Engineering, Vol. 114, 1992, pp. 566-576.[CrossRef]

Eckerle, W.A. and Awad, J.K., Effect of Freestream Velocity on the Three-Dimensional Separated Flow Region in Front of a Cylinder, J. Fluids Engineering, Vol. 113, 1991, pp. 37-44.[CrossRef]

Eckerle and Langston, Horseshoe Vortex Formation around a Cylinder, ASME J. of Turbomachinery, Vol. 109, April 1987, pp. 278-285.

Monnier, J.C. and Stanislas, M., Study of a Horseshoe Vortex by LDV and PIV, ERCOFTAC Bulletin, No. 30, 1996, pp. 19-24.

Pierce, F.J. and Tree, I.K., The Mean Flow Structure and the Symmetry Plane of a Turbulent Junction Vortex, J. Fluids Engineering, Vol. 112, 1990, pp. 16-22.[CrossRef]

Barbhuiya, A.K. and Dey, S., Measurement of Turbulent Flow Field at a Vertical Semicircular Cylinder Attached to The Sidewall of a Rectangular Channel, Flow Measurement and Instrumentation, Volume 15, Issue 2, April 2004, Elsevier, pp. 87-96.

Yulistiyanto, B., Zech, Y., and Graf, W.H., Free-Surface Flow around a Cylinder: Shallow-Water Modeling with Diffusion-Dispersion, Journal of Hydraulic Engineering, Vol. 124 (no.4), 1998, pp. 419-429.[CrossRef]

Andreas, R, Mutlu Sumer, B., Jorgen, F., and Jess, M., Numerical and Experimental Investigation of Flow and Scour around a Circular Pile, Journal of Fluid Mechanics, 534, Cambridge, 2005, pp. 351-401.

Barbhuiya, A.K. and Dey, S., Velocity and Turbulence at a Wing-Wall Abutment, Sadhana, Vol. 29, Part 1, February 2004, India, pp. 35–56.

Graf W.H. and Altinakar, M.S., Hydraulique Fluviale, Tome 1, Presses Poly. et Univ. Romandes, Lausanne, CH, 1993.

Yusron, S., Fractional Critical Shear Stress at Incipient Motion in a Bimodal Sediment, Civil Engineering Dimension, Vol. 10, No. 2, September 2008, pp. 89-98.

Graf, W.H. and Yulistiyanto, B., Experiments on Flow around a Cylinder; the Velocity and Vorticity Fields, J. Hydraulic Research, Vol. 36, 1998, pp. 637-653.[CrossRef]

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Published

2010-08-26

How to Cite

B., Y. (2010). Flow Fields in front of a Cylindrical Obstacle. Civil Engineering Dimension, 12(2), 79-91. https://doi.org/10.9744/ced.12.2.79-91

Issue

Vol. 12 No. 2 (2010): SEPTEMBER 2010

Section

Articles

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