Library Subscription: Guest
Begell Digital Portal Begell Digital Library eBooks Journals References & Proceedings Research Collections
International Journal of Fluid Mechanics Research
ESCI SJR: 0.22 SNIP: 0.446 CiteScore™: 0.5

ISSN Print: 2152-5102
ISSN Online: 2152-5110

International Journal of Fluid Mechanics Research

DOI: 10.1615/InterJFluidMechRes.v32.i4.60
pages 488-510

Pseudo-Sound Behind an Obstacle on a Cylinder in Axial Flow

V. A. Voskoboinick
Institute of Hydromechanics of National Academy of Sciences of Ukraine 8/4, Zhelyabov St., Kyiv, 03057, Ukraine
A. P. Makarenkov
Institute of Hydromechanics of National Academy of Sciences of Ukraine, Kyiv

ABSTRACT

Pseudo-sonic fluctuations of the wall pressure behind a ring-shaped obstacle on a flexible extended cylinder in longitudinal flow of fluid have been experimentally investigated. Integral and spectral statistical characteristics of pressure fluctuation field behind the obstacle have been obtained and its influence on the structure of the turbulent boundary layer has been investigated. Putting the obstacle in the interior of the boundary layer changes the structure of the whole boundary layer. As the obstacle diameter increases, the intensity of the near-wall pressure fluctuations grows. The maximum intensity is observed in the near wake of the obstacle. At the distances exceeding 100 diameters of the obstacle, the turbulent boundary layer recovers. An increase of the obstacle diameter and flow velocity results in a growth of the low-frequency spectral components of pressure fluctuations and in a decay of the high-frequency components, compared to a boundary layer on hydraulically smooth cylinder. The turbulent boundary layer behind the obstacle is saturated with large-scale vortical structures. The biggest contribution to the energy of the pseudo-sonic pressure fluctuation field is made by the vortices shedded from an obstacle transverse to the flow, the frequencies of those conforming to the Strouhal number Sh ≈ 0.1. In the subcritical regime of the separation flow on the ring obstacle, the Strouhal number is inversely proportional to the Reynolds number.


Articles with similar content:

Amplitude Modulation of Pressure in Turbulent Boundary Layer
TSFP DIGITAL LIBRARY ONLINE, Vol.9, 2015, issue
Ivan Marusic, Arne V. Johansson, Yoshiyuki Tsuji
Instantaneous Flow Field above the Free-end of Finite-height Cylinders and Prisms
ICHMT DIGITAL LIBRARY ONLINE, Vol.0, 2012, issue
Donald J. Bergstrom, James D. Bugg, Noorallah Rostamy, David Sumner
NEAR-WALL INFLUENCE OF LARGE-SCALE MOTIONS IN HIGH REYNOLDS NUMBER TURBULENT BOUNDARY LAYERS
TSFP DIGITAL LIBRARY ONLINE, Vol.6, 2009, issue
Ivan Marusic, H. Ng, Nicholas Hutchins, Jason P. Monty, Bharath Ganapathisubramani
NOVEL PHENOMENA IN TURBULENT ELLIPTIC WAKES
TSFP DIGITAL LIBRARY ONLINE, Vol.1, 1999, issue
Masaru Kiya, Hitoshi Ishikawa, Yukinobu Abe, Osamu Mochizuki
NOVEL PHENOMENA IN TURBULENT ELLIPTIC WAKES
Turbulence and Shear Flow Phenomena -1 First International Symposium, Vol.0, 1999, issue
Masaru Kiya, Hitoshi Ishikawa, Yukinobu Abe, Osamu Mochizuki