Stretching and tilting of material lines in turbulence: The effect of strain and vorticity

@article{guala06, abstract = {The Lagrangian evolution of infinitesimal material lines is investigated experimentally through three dimensional particle tracking velocimetry (3D-PTV) in quasihomogeneous turbulence with the Taylor microscale Reynolds number Re=50. Through 3D-PTV we access the full tensor of velocity derivatives ui/xj along particle trajectories, which is necessary to monitor the Lagrangian evolution of infinitesimal material lines l. By integrating the effect on l of (i) the tensor ui/xj, (ii) its symmetric part sij, (iii) its antisymmetric part rij, along particle trajectories, we study the evolution of three sets of material lines driven by a genuine turbulent flow, by "strain only," or by "vorticity only," respectively. We observe that, statistically, vorticity reduces the stretching rate liljsij/l2, altering (by tilting material lines) the preferential orientation between l and the first (stretching) eigenvector 1 of the rate of strain tensor. In contrast, sij, in "absence" of vorticity, significantly contributes to both tilting and stretching, resulting in an enhanced stretching rate compared to the case of material lines driven by the full tensor ui/xj. The same trend is observed for the deformation of material volumes.}, author = {Guala, Michele and Liberzon, Alexander and Luthi, Beat and Kinzelbach, Wolfgang and Tsinober, Arkady }, citeulike-article-id = {778995}, doi = {10.1103/PhysRevE.73.036303}, journal = {Physical Review E (Statistical, Nonlinear, and Soft Matter Physics)}, keywords = {alignment, material-lines, small-scales}, number = {3}, posted-at = {2006-07-28 23:56:36}, priority = {2}, publisher = {APS}, title = {Stretching and tilting of material lines in turbulence: The effect of strain and vorticity}, url = {http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal\&id=PLEEE8000073000003036303000001\&idtype=cvips\&gifs=yes}, volume = {73}, year = {2006} }

TY - JOUR ID - guala06 L3 - citeulike-article-id:778995 TI - Stretching and tilting of material lines in turbulence: The effect of strain and vorticity JF - Physical Review E (Statistical, Nonlinear, and Soft Matter Physics) VL - 73 IS - 3 PB - APS N2 - The Lagrangian evolution of infinitesimal material lines is investigated experimentally through three dimensional particle tracking velocimetry (3D-PTV) in quasihomogeneous turbulence with the Taylor microscale Reynolds number Re=50. Through 3D-PTV we access the full tensor of velocity derivatives ui/xj along particle trajectories, which is necessary to monitor the Lagrangian evolution of infinitesimal material lines l. By integrating the effect on l of (i) the tensor ui/xj, (ii) its symmetric part sij, (iii) its antisymmetric part rij, along particle trajectories, we study the evolution of three sets of material lines driven by a genuine turbulent flow, by "strain only," or by "vorticity only," respectively. We observe that, statistically, vorticity reduces the stretching rate liljsij/l2, altering (by tilting material lines) the preferential orientation between l and the first (stretching) eigenvector 1 of the rate of strain tensor. In contrast, sij, in "absence" of vorticity, significantly contributes to both tilting and stretching, resulting in an enhanced stretching rate compared to the case of material lines driven by the full tensor ui/xj. The same trend is observed for the deformation of material volumes. KW - alignment KW - material-lines KW - small-scales AU - Guala, Michele AU - Liberzon, Alexander AU - Luthi, Beat AU - Kinzelbach, Wolfgang AU - Tsinober, Arkady PY - 2006/// UR - http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PLEEE8000073000003036303000001&idtype=cvips&gifs=yes ER -