An Investigation into Anti-Swirl Devices for S-Shaped Air Intakes

摘要

The paper presents the results of an investigation into the effectiveness of streamwise fences as anti-swirl devices for use in an S-shaped duct of typical air intake proportions. Fences were positioded in the first bend of the duct on the lower and outside walls. The effects of twelve configurations of such fences of varying heights have been studied. The swirl characteristics over an incidence range of 10 deg to 30 deg were measured in terms of swirl coefficient (SC sub 60), distortion coefficient (DC sub 60) and pressure recovery. In addition static pressures at the wall were measured either side of the fences. It was found that all fence configurations tested improved the swirl characteristics of the duct (by arresting rotational flow in the first bend), and indeed the swirl direction could be reversed. The configuration consisting of a lower and side fence meeting on the center-line of the duct was found to possess the most favorable characteristics of the configurations tested.