The observation of small-scale velocity structures in high Reynolds number turbulent flow fields is important for the understanding of energy scaling and dissipation phenomena. The RELIEF technique is shown to be a promising tool to observe these scales. Lines on the order of 100 microns thick and 1 cm long are written into a turbulent free jet and observed with a resolution on the order of tens of microns. The images which are recorded give instantaneous velocity profiles if very short time delays between tagging and interrogation are used. This data leads to measurements of the turbulence intensity, the lateral correlation function, and the Taylor microscale. The second-order structure function is also found and, at 30 diameters downstream, a slope of 0.667 is measured in the linear portion of the ln-ln plot of the inertial subrange. This is in accord with the Kolmogoroff energy scaling relationship.
Fundamental turbulence measurement by relief flow tagging
Grundsätzliche Messungen der Turbulenz unter Zuhilfenahme der Ablösungsströmungsmarkierung
AIAA-Papers ; 1-6
1992
6 Seiten, 14 Bilder, 9 Quellen
Aufsatz (Konferenz)
Englisch