2008/10/19 by Peter E. Hamlington, Jörg Schumacher, Werner J. A. Dahm · 1 citation
Physics and Astronomy · #physics.flu-dyn
paper · pdf · doi:10.1063/1.3021055
published as Phys. Fluids 20, 111703 (2008) · 5 pages, 5 figures, to appear as a Letter in Physics of Fluids
arxiv created 2008/10/19 · arxiv updated 2009/12/01
A direct Biot-Savart integration is used to decompose the strain rate into its local and nonlocal constituents, allowing the vorticity alignment with the local and nonlocal strain rate eigenvectors to be investigated. These strain rate tensor constituents are evaluated in a turbulent flow using data from highly-resolved direct numerical simulations. While the vorticity aligns preferentially with the intermediate eigenvector of the combined strain rate, as has been observed previously, the present results for the first time clearly show that the vorticity aligns with the most extensional eigenvector of the nonlocal strain rate. This in turn reveals a significant linear contribution to the vortex stretching dynamics in turbulent flows.