Second Symposium on Turbulence and Shear Flow Phenomena
DOI: 10.1615/TSFP2
NONUNIFORM STRETCHED WEIGHT IN LINE STATISTICS OF TURBULENCE
pages 263-268
DOI: 10.1615/TSFP2.2070
ABSTRAKT
Statistics of passive material lines in homogeneous isotropic turbulence are investigated by the use of direct numerical simulations. Passive material lines are stretched locally by the Kolmogorov-scale vortices, and their total length increases exponentially in time with the stretching rate of 0.17 (Kolmogorov time)−1 at the Taylor-micro-scale Reynolds numbers of 56 and 84. It is shown theoretically and numerically that the commonly used simple arithmetic mean of stretching rates of many infinitesimal line elements underestimates the real stretching rate of passive material lines owning to nonuniform stretching along the lines.