Effect of Cylinder Roughness on Strouhal Number

0583372 - ÚT 2024 CZ eng C - Conference Paper (international conference)
Yanovych, Vitalii - Duda, D. - Uruba, Václav - Procházka, Pavel P. - Antoš, Pavel
Effect of Cylinder Roughness on Strouhal Number.
Proceedings of Topical Problems of Fluid Mechanics 2022. Prague: Institute of Thermomechanics AS CR, 2022 - (Šimurda, D.; Bodnár, T.), s. 201-207. ISBN 978-80-87012-77-2. ISSN 2336-5781.
[Topical Problems of Fluid Mechanics 2022. Prague (CZ), 16.02.2022-18.02.2022]
R&D Projects: GA TA ČR(CZ) TH02020057
Institutional support: RVO:61388998
Keywords : roughened cylinder * Strouhal number * spectral distribution * turbulence structure * Hot-wire anemometry
OECD category: Applied mechanics
http://www2.it.cas.cz/fm2015/im/admin/showfile/data/my/Papers/2022/27-TPFM2022.pdf

The main goal of this paper is to establish a better understanding of the relationship between a Strouhal number and surface roughness. Hot-wire anemometry was used to evaluations the characteristics of turbulent flow behind circular cylinders with different relative roughness 0% (smooth surface) 0.83%, 1.67%, 3.33%, and 6.67%. At the experimental investigation, the Reynolds number based on the cylinder diameter was 5 × 103 < Red < 2 × 104. The obtained data showed that the Strouhal number decreased with increasing roughness. While, the dissipation rate decreases, and the value of the Kolmogorov and Taylor microscales increases. Also, spectral analysis of streamwise velocity fluctuations allowed us to estimate the location of the vortex-shedding frequency which at growing roughness tends to reduce.
Permanent Link: https://hdl.handle.net/11104/0351828