Paper 25: Two-Dimensional Subsonic Flow in a Parallel Diffuser

From the laws of conservation of mass, momentum and energy, predictions are made of subsonic flow conditions between parallel surfaces of infinite depth under the influence of a positive pressure gradient. The model employed presupposes a boundary layer outside a main stream across which the flow parameters are uniform. The theory suggests limitations on boundary-layer thickness, and indicates velocity profiles differing substantially from that of a conventional turbulent boundary layer. Owing to momentum exchange between the free stream and the boundary layer, limitations on the static pressure ratio and the length of the diffuser also appear to be implied.