Further Experiments With Suction at a Sudden Enlargement in a Pipe

Abstract

Previously reported experiments on incompressible flow through a step expansion in a pipe, as influenced by suction at the smaller diameter of the step, have been extended to examine effects of inlet flow on suction requirements and performance of the device as a (short) diffuser. Here the performance for a fully developed turbulent pipe flow is considered and compared to previous results for an inlet flow with thin boundary layer. Whenever overall diffuser length is restricted to values less than some upper limit for a given expansion ratio, then for either inlet flow condition, the present device is shown to produce higher pressure recoveries (adjusted for suction power) than conical diffusers.