Investigation of a Laminar Boundary-Layer Suction Slot

The flow of a laminar boundary layer into a suction slot has been examined experimentally in a low-turbulence water channel. Dimensional analysis shows that the slot Reynolds number and a parameter that describes the mean velocity gradient in the flow above the slot are the important variables in the problem. Measurements are reported of the length scales of the separation region within the slot and the slot-pressure loss. These data correlate in terms of the similarity variables and may be used as a predictive design tool. The mean-flow profiles above the slot, in both the upstream and downstream directions, were also measured using hot films, and the possibility of a Taylor-Gortler rotational instability occurring just downstream of the slot has been studied.