Effects of diffuser vane geometry on interaction noise generated from a centrifugal compressor

Abstract

The characteristics of interaction tone noise radiated from a centrifugal compressor with a vaned diffuser are discussed by experiments, including visualization techniques using the oil-film method. Research attention is paid to the leading edge geometries of the diffuser vanes that are deeply related to the generation mechanism of the interaction tone noise. The compressor-radiated noise can be reduced by several decibels by setting some clearances in both the hub and shroud surfaces of the diffuser wall along with some decline in the pressure-rise coefficient. Since the decline turned out to be caused by the flow impingement and also by the secondary flow within the diffuser passages, several new types of diffuser vane geometries which do not detract from both the performance and noise level are developed and utilized for the experiments. The presented diffuser vane geometries will offer a few basic guidelines for the diffuser vane design.

Effects of tapered diffuser vane on the flow field and noise of a centrifugal compressor

“…Please refer to the previous paper [4,5] for further details of the tested compressor and tapered diffuser vanes.…”

“…The authors have already shown by experiments and also by flow visualization technique that the leading-edge shape of the diffuser vane may play an important role in both noise generation and compressor performance, and the tapered diffuser vanes which have three-dimensional tapered shapes on both the pressure and suction surfaces of the diffuser leading edge can reduce the noise level of the ITN effectively without any influence on the compressor performance [4,5].…”

Aerodynamic performance and noise characteristics of a centrifugal compressor with modified vaned diffusers

“…The specifications of the tested centrifugal compressor and dimensions of the impeller and vaned diffuser are listed in Table 1. Refer to the related report [6] for further details of the tested compressor. Three types of tapered diffuser vanes, type A, B and C, are designed and utilized for the experiment.…”

“…2. The diffuser vane height BB T at the leading edge is experimentally decided at 40% which is considered to be the most effective for both the compressor performance and the overall noise level [6]. By attaching the three types of modified vanes on the vaneless diffuser, noise, performance and unsteady pressure measurements are carried out under various conditions.…”

“…The authors have already shown by experiments and also by flow visualization technique that the leading edge shape of the diffuser vane may play an important role in both the noise generation and the compressor performance, and the tapered diffuser vanes which have three-dimensional tapered shapes on both pressure and suction surfaces of the diffuser leading edge can reduce the noise level of the ITN effectively without any slight influence on the compressor performance [6].…”