Low-Speed Axial Compressor
All measurements were performed on the highly-loaded, single-stage, low – speed axial compressor shown in Figure 1. The test stage is designed with custom tailored CDA profiles and uses an inlet guide vane (IGV) to ensure that the inlet swirl to the following stage is truly representative of middle stage of a high-pressure compressor [3]. The axial compressor has a maximum capacity of m=9 kg/s at a speed of n=2800 rpm. The rotor consists of 43 blades, while the stator and the inlet guide vane use 45 vanes. The rotor as well as the stator blade chord is 1=75 mm and the aspect ratio is h/1=1.0. The axial distance between the blade rows is about 50% chord at mid-span. The test section of the compressor has a casing diameter of DC=600 mm and a hub diameter of DH =450 mm with parallel annulus lines at constant inner and outer radii. The maximum motor power is Pmax=58 kW and allows a free-stream velocity of U=60 m/s. The measured compressor performance characteristics are presented in Figure 2. The diagram shows three different trend lines of the static pressure ratio and the efficiency n due to a mass fbw variation. In addition, the operating points of interest are marked in the diagram.