Analysis of Turbulence Characteristics in the Laminar Sub-Layer Region of a Perturbed Turbulent Boundary Layer

Abstract:

Turbulent boundary layer plays an important role for generation of aerodynamic drag. Shear force and pressure force due to the presence of boundary layer separation from the body surface contribute to the total drag. Studies of drag reduction due the the boundary layer effect are continuously performed by many researchers. Present study is intended to evaluate the behaviour of the laminar sub-layer in a turbulent boundary layer using a hot-wire anemometer system. The study was conducted in a low-speed wind tunnel at a Reynolds number based on the momentum thickness of approximately Re_θ = 1000. A smooth-flat plate and a plate with a single transverse square groove was used in the study of the boundary layer characteristics. The groove size of 10 mm x 10 mm was cut transversally across the test plate. The results show that no significant differences in the streamwise mean velocity, steamwise turbulence intensity, and velocity signals for the smooth-and grooved-wall cases. For the the energy spectra for the two cases, however, show significant differences.

• Periodical: Applied Mechanics and Materials (Volume 836)
• Pages: 115-120
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.836.115
• Online since: June 2016
• Authors: Sutardi Sutardi*, Wawan Aries Widodo
• Keywords: Hot-Wire Anemometer, Laminar Sub-Layer, Square Goove, Turbulence Intensity, Turbulent Boundary Layer

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