The structure of a turbulent shear layer bounding a separation region

摘要: Detailed measurements within the separated shear layer behind a flat plate normal to an airflow are reported. A long, central splitter in wake prevented vortex shedding and led extensive region of flow with mean reattachment some ten heights downstream. The Reynolds number based on height was excess 2 × 1044.Extensive use pulsed-wire anemometry allowed all stresses throughout flow, along velocity autocorrelations integral timescale data. latter help substantiate results other workers obtained flows related geometry, particularly identification very low-frequency motion much longer than that associated large eddies layer. Wall-skin-friction consistent few similar data previously published indicate thin boundary developing beneath has ‘laminar-like’ features.The Reynolds-stress demonstrate turbulence structure differs from plane mixing between two streams ways. In particular, rise monotonically as is approached, always considerably higher values develop quite different Flow similarity not useful concept. major conclusion any effects stabilizing streamline curvature weak compared re-entrainment at low-velocity edge turbulent fluid returned around reattachment. It argued general features likely be those occur wide range complex dominated by bounding large-scale recirculating region.