DOI: 10.1615/TSFP6
EXPERIMENTAL AND MODELLING STUDY OF TURBULENCE UNDER ZERO-MEAN-FLOW CONDITIONS
ABSTRAKT
Symmetry analysis of the evolution equation for the two-point correlation tensor Rij (xk,ri,t) in the case of planar generation of turbulence in an otherwise calm semi-infinite body of fluid has revealed some interesting solutions concerning the statistical properties of turbulence and how they develop with distance from the generation source. The first solution concerns the classical case of shear-free turbulent diffusion. Here, the turbulent kinetic energy is distributed according to a power law x−n where n is a constant larger than one, and x is the normal distance to the forcing plane. The integral length scales of turbulence increase linearly with x. A second case is considered when the symmetry of scaling of space is broken by introducing confinement to the flow. The turbulent kinetic energy decays with x as exp(−x) and the integral length scales remain constant along x. The purpose of the present work is to investigate the propagation of the interface separating the turbulent from the non-turbulent (turbulent/non-turbulent interface, TNTI) flow regions, for the two cases using particle image velocimetry (PIV) and large eddy simulation (LES).