Characteristics of curvature and torsion of particle trajectories are investigated by using direct numerical simulations. Curvature, torsion and their ratio are expected to have crucial roles in identification of the vortical structures. Curvature and torsion are highly intermittent and their PDFs show a rigorous slope in log-log scale which indicates selfsimilar power-law behavior. It is well known that extremely high curvature comes from nearly zero-velocity event, but for the case of torsion it is not clealy explained. We found that the magnitude of torsion is determined mainly by the magnitude of |a|/|an||u|, but detailed physical interpretation of |a|/|an||u| is required. Enstrophy-conditional PDF and various Stokes number cases for heavy particles are also investigated, but they give almost the same shape of PDF, and that self-similar characteristics of curvature and torsion are not related with turbulent structures.
|Publication status||Published - 2011|
|Event||7th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2011 - Ottawa, Canada|
Duration: 2011 Jul 28 → 2011 Jul 31
|Other||7th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2011|
|Period||11/7/28 → 11/7/31|
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea Grant funded by the Korean Government (MEST)" (NRF-2010-8-1872) and 20090093134 (ERC Program).
All Science Journal Classification (ASJC) codes
- Fluid Flow and Transfer Processes