The Influence of Outlet Stator Part Surface Roughness on the Performance of a Very Low Flow Coefficient Centrifugal Compressor Stage

Abstract

An aerodynamic investigation of the influence of outlet stator part (vaneless diffuser and return channel) surface roughness on aerodynamic performance of a very low flow coefficient centrifugal stage has been carried out. The stage with design inlet flow coefficient 0.007 was tested within the range of stage Mach number Mu2=0.5–1.1. Then the surface quality of outlet stator part was improved and the tests have been repeated. Aerodynamic performance and losses in both vaneless diffuser and return channel with de-swirl vanes were investigated. The values of isentropic head coefficient increased while those of loss coefficient decreased nearly in the whole range of characteristics in the stage with improved surface quality. The detailed pressure recovery in vaneless diffuser in vicinity of design point measured and calculated by the performance prediction method is compared and discussed. The nonsteady flow phenomena were also investigated. The change of dynamic stability limit by improving of surface quality was observed.

Experimental investigation and numerical modelling of 3D radial compressor stage and influence of the technological holes on the working characteristics

“…The description of the planes in the stage is longterm used, see [3]. The main evaluation planes are the planes 0 and 7 depicted in the bottom part of Fig.…”

Numerical and experimental modelling of the centrifugal compressor stage – setting the model of impellers with 2D blades

“…1 down. The description of the planes in the stage is long-term used, see [4]. There is a number of static and total pressure and total temperature probes (multiple sensors are placed in main evaluation planes 0 and 7).…”

Numerical modelling and experimental investigation of the influence of selected geometric elements on the working characteristics of radial compressor stages with prismatic blades

“…The described development of the centrifugal compressor stages was a continuation of the systematic research and long term development program; see for example the paper [2]. Experimental measurements were realized in the development test facility Howden ČKD Compressors Ltd. in Pilsen from 2014 to 2018, where the single-stage test compressor DARINA IV with the exchangeable flow part was placed.…”

“…The flow parameters are measured in large number of points on the evaluation planes. The labels of the planes in the stage are long-term used, see [2], and are depicted in Fig. 2; the main evaluation planes or so called measuring stations for determination of the stage parameters are the stations 0 and 7.…”