TY - JOUR
TI - TURBULENT DISSIPATION RATE MEASUREMENTS IN PLANE AND AXISYMMETRIC WAKE FLOWS
AU - Schenck Toralf C
AU - Jovanović Jovan
JN - Thermal Science
PY - 2001
VL - 5
IS - 1
SP - 75
EP - 100
PT - Article
AB - All first-order spatial derivatives of the turbulent velocity fluctuations were measured using a pair of X hot-wire probes. Measurements were performed in the self-preserving region of a turbulent plane wake downstream of a cylinder and in an arisymmetric wake behind the sphere. Good spatial resolution of the measurements was ensured by choosing small values for the cylinder/sphere diameter and a low flow speed. 
Errors due to the finite hot-wire length and the wire and probe separation were analysed using Wyngaard's correction method. The derived corrections were verified experimentally. 
The measuring technique and the experimental results were systematically checked and compared with the results available in the literature. The assumptions of local isotropy and local axisymmetry were examined. Both investigated flows deviate only moderately from local isotropy and local arisymmetry. Support for the measured results 1s provided by plotting the data on an anisotropy invariant map. The budgets of the turbulent kinetic energy were computed from the measured data. In contrast to the
results obtained in the plane wake, where the pressure transport 1s nearly negligible, in the axisymmetric wake it was found to play an important role and closely follows the estimate made by Lumley, <span style="text-decoration:overline">u<sub>i</sub>p</span>/ρ ≈ —0.2<span style="text-decoration:overline">q<sup>2</sup>u<sub>i</sub></span>.