SLESSOR, M. D., BOND, C. L., and DIMOTAKIS, P. E.   1998   "Turbulent shear-layer mixing at high Reynolds numbers: effects of inflow conditions," J. Fluid Mech.   vol. 376, 115-138.


We report on the results from a set of incompressible, shear-layer flow experiments, for high local Reynolds numbers, i.e.,

Red  =  rm DU dT(x) / mm  =  2 x 105 ,

where rm is the density of fluid mixed at the entrainment ratio, DU = U1-U2 is the shear-layer freestream velocity difference, dT is the 1% temperature-rise thickness for chemically-reacting shear layers, and mm is the viscosity of fluid mixed at the entrainment ratio). In these experiments, the inflow conditions of shear-layer formation were varied. Both inert and chemically-reacting flows were investigated; the latter employing the (H2+NO) / F2 chemical system, in the kinetically-fast regime, to measure molecular mixing. Inflow conditions were varied by perturbing each, or both, boundary layers on the splitter plate separating the two freestream flows, upstream of shear-layer formation.

The results of the chemically-reacting "flip experiments" reveal that seemingly-small changes in inflow conditions can have a significant influence not only on the large-scale structure and shear-layer growth rate, as had been documented previously, but also on molecular mixing and chemical-product formation, far downstream of the inflow region.