Investigation of the Swirling Flow in a Suction Pipe with Inlet Guide Vanes. Experimental Studies of the Swirling Flow in a Suction Pipe of a Centrifugal Compressor.

Abstract

The swirling flow in a suction pipe with inlet guide vanes was experimentally studied. It was observed that the periodical pressure and velocity oscillations occurred when the guide vane angle was set at middle opening in a pipe in which a disk inserted downstream from the inlet guide vanes. The wall pressure and velocity distribution were measured in various conditions where the inlet guide vane angle and the disk position were changed. It was found that the velocity and wall pressure oscillations were strongly related to each other and that they proceed from upstream to downstream in a pipe with swirling. This phenomenon was considered to be induced by spiral vortices. An operating test showed that the similar phenomenon occurred in a centrifugal compressor suction pipe and a countermeasures to suppress the rotor whirling vibration was valid in which the inlet guide vanes were set adjacent to a compressor impeller.