Download or read book Aspects of Turbulent-Shear-Layer Dynamics and Mixing written by Michael David Slessor and published by . This book was released on 1998 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experiments have been conducted in the GALCIT Supersonic Shear Layer Facility to investigate some aspects of high Reynolds number, turbulent, shear layer flows in both incompressible and compressible flow regimes. Experiments designed to address several issues were performed; effects of inflow conditions, freestream conditions (supersonic/subsonic flow), and compressibility, on both large scale dynamics and small scale mixing, are described. Chemically reacting and non reacting flows were investigated, the former relying on the (H2+NO)/F2 chemical system, in the fast-kinetic regime, to infer the structure and amount of molecular scale mixing through use of "flip" experiments. Both inflow conditions and compressibility are found to have significant effects on the flow. In particular, inflow conditions are "remembered" for long distances downstream, a sensitivity similar to that observed in low-dimensionality, nonlinear (chaotic) systems. A previously proposed mode selection rule for turbulent structure convection speeds, based on the presence of a lab frame subsonic freestream, was demonstrated to be incorrect. Compressibility, when decoupled from other parameters, e.g., Reynolds number, velocity and density ratios, reduces large scale entrainment and growth, but slightly enhances mixing, and changes the molecularly mixed fluid structure. This reduction in shear layer growth rate is examined and a new parameter that interprets compressibility as an energy exchange mechanism is proposed. The parameter reconciles and collapses experimentally observed growth rates.