Separated Flow in Curved Channels with Secondary Injection

摘要

Injection of secondary fluid flow into a primary flow confined in a curved channel is shown to be a powerful technique for use in fluid state amplification. The secondary injection continuously and progressively alters the separation characteristics of the confined primary flow, resulting in large proportional changes in the channel output flows. A fundamental study of the method with incompressible, turbulent boundary layer flow in a range of varying curvature channels was conducted to learn about the flow characteristics and passage shape parameters relevant to proportional amplification. Several injection methods and velocities were investigated with the main emphasis on the effects of this injection on the flow characteristics within the channels. Preliminary analytical techniques were developed which compared favorably with the experimental results. An overall comparison of the mass flow and momentum gains obtainable for various injection and channel configurations is presented. (Author)