Spanwise-invariant three-dimensional separated flow

Pulsed-wire measurements of mean velocity and Reynolds stresses have been made in a spanwise-invariant, three-dimensional separated flow; the flow is two-dimensional but not coplanar. Three layers have been identified. The effects of three-dimensionality arise mainly in the inner layer (adjacent to the surface), in which the mean flow appears to be locally coplanar, and the effect of the transverse flow in the middle and outer layers is largely inviscid, the flow largely scaling with the component of free-stream velocity perpendicular to the separation line. The lateral mean velocities closely exhibit a ''velocity triangle'' relation like that found in boundary layers, even in the reverse-flow region. The stresses in the outer layer fall close to those in a plane mixing layer; whereas, in the middle layer, they are higher. (C) Elsevier Science Inc., 1997.