@article{discovery1299360, volume = {670}, year = {2011}, title = {Break-away separation for high turbulence intensity and large Reynolds number}, month = {March}, journal = {J FLUID MECH}, pages = {260 -- 300}, note = {{\copyright} 2011 Cambridge University Press}, publisher = {CAMBRIDGE UNIV PRESS}, keywords = {boundary layer separation, boundary layers, turbulent flows, BOUNDARY-LAYER, BLUFF-BODY, ASYMPTOTIC THEORY, LAMINAR-FLOW, TRAILING-EDGE, BODIES, WAKES}, issn = {0022-1120}, url = {http://dx.doi.org/10.1017/S0022112010005306}, author = {Scheichl, B and Kluwick, A and Smith, FT}, abstract = {Massive flow separation from the surface of a plane bluff obstacle in an incompressible uniform stream is addressed theoretically for large values of the global Reynolds number Re. The analysis is motivated by a conclusion drawn from recent theoretical results which is corroborated by experimental findings but apparently contrasts with common reasoning: the attached boundary layer extending from the front stagnation point to the position of separation never attains a fully developed turbulent state, even for arbitrarily large Re. Consequently, the boundary layer exhibits a certain level of turbulence intensity that is linked with the separation process, governed by local viscous-inviscid interaction. Eventually, the latter mechanism is expected to be associated with rapid change of the separating shear layer towards a fully developed turbulent one. A self-consistent flow description in the vicinity of separation is derived, where the present study includes the predominantly turbulent region. We establish a criterion that acts to select the position of separation. The basic analysis here, which appears physically feasible and rational, is carried out without needing to resort to a specific turbulence closure.} }