Inlet Distortion of a Centrifugal Compressor With a Circular-Sectioned 90-Degree Bend and Its Influence on the Performance

Abstract

In this study, distortion due to inlet duct is experimentally analyzed and discussed in order to understand the performance characteristics of the compressor exposed to a curved inlet configuration. The flow from the bend inlet is not axisymmetric in the circumferential and radial distortion. In the combination including a centrifugal compressor, the bend inlet due to spatial limitation has been shown in a various applications such as industrial chiller. The performance of centrifugal compressors can be degraded by inlet flow distortion due to a 90 degree curved pipe. The bend have some curvature radius ratio, straight upstream and downstream pipes. The flow in bend inlet is sucked due to rotating of impeller and not axisymmetric in the circumferential and radial distortion. In general, primary flow and secondary flow are occurred in curved pipe. In this paper, flow at curved pipe was experimentally measured using by 5-hole probe and hot-wire probe. The 5-hole probe was used in observing the total pressure and velocity contour. Also, the measurement of hot-wire probe was carried out in order to obtain a streamwise velocity profile. The flow details are analyzed and discussed in order to understand the relation between inlet distortion and aerodynamic performance.