Book Description

The passage vortex associated with secondary flows appears to be near the suction surface and away from the plane wall of the elbow at the exit and does not have appreciable spanwise motion as it moves downstream the elbow exit. As the spoiler size increases, the boundary-layer form changes and a rather sudden difference in the secondary flow occurs, perhaps associated withthe reduced importance of viscous effects in thick boundary layers. It is suggested that the strength of the secondary vortices is small and that the energy of secondary flows is small.