Lagrangian velocity statistics obtained from direct numerical simulations of homogeneous turbulence
Abstract
Lagrangian statistics of velocity, acceleration and dissipation have been studied using direct numerical simulations. The simulated flows are statistically homogeneous, isotropic and stationary, with energy maintained by artificially forcing the lowwavenumber components. A numerical algorithm for tracking fluidparticles recently developed by the authors is used to extract Lagrangian statistics. Lagrangian velocity autocorrelations, frequency spectra and structure functions have been calculated. Lagrangian velocity increments are found to be highly intermittent and nonGaussian. Dissipation is approximately lognormally distributed, and highly correlated with the fluid particle acceleration. The range of (Taylormicroscale) Reynolds numbers treated (2050) is presumably not high enough for the predictions by the Kolmogorov 1941 similarity hypotheses to apply.
 Publication:

6th Symposium on Turbulent Shear Flows
 Pub Date:
 1987
 Bibcode:
 1987stsf.proc....3Y
 Keywords:

 Acceleration (Physics);
 Computerized Simulation;
 EulerLagrange Equation;
 Homogeneous Turbulence;
 Statistical Analysis;
 Algorithms;
 NavierStokes Equation;
 Reynolds Number;
 Transport Properties;
 Velocity Distribution;
 Fluid Mechanics and Heat Transfer