Author(s): Min Cheol Song; Jin Hwan Hwang
Linked Author(s): Jin Hwan Hwang
Keywords: Turbulent dissipation; Wake flow; PIV
Abstract: Measuring the turbulent dissipation rate ε in a cylinder wake plays a key role in turbulence models (e.g., k–ε models) and eddy viscosity estimations. However, direct measurement of ε is difficult because it involves velocity gradients at the Kolmogorov scale, which often exceeds the spatial or temporal resolution of experimental setups. Although 3D Particle Image Velocimetry (3D-PIV) offers a measurement of velocity fields, obtaining the full dissipation spectrum from the time-domain frequency range is still limited. In this study, we address this issue by extending the dissipation spectrum beyond the measurable frequency range. We validate an extension method that leverages the Taylor frozen-flow hypothesis and local isotropy assumption to recover the unmeasured portion of the spectrum, thereby enabling a more accurate estimation of ε.
Year: 2025