Description of Experiment Stage Matching Investigation Rig

Experiments were conducted in the Stage Matching Investigation (SMI) transonic compressor rig at the Air Force Research Lab (AFRL). The rig con­sists of a high-speed, highly loaded rotor followed by a row of stator vanes. A row of wake generators (WGs), similar to inlet guide vanes (IGVs), is installed upstream of the rotor to simulate an embedded stage. The rig was originally designed to investigate upstream wake infhences on stage ft>w matching [9]. However, with the adjustability of the WG forcing function and the addition of rotor-mounted strain gauges, the rig has recently proven useful for forced response experiments.

A schematic of the SMI rig flwpath with WGs installed is provided in Fig. 5. The fan is a 19-in (48.3 cm) diameter integrally bladed disk (or blisk) with 28 blades of 0.916 average aspect ratio. The rotor has a design speed of 16,400 RPM, with hub and tip relative Mach numbers of 1.10 and 1.39, respectively. The stator row is composed of 49 vanes with 0.824 average aspect ratio. Design fbw capacity is 34.5 lbm/s (15.6 kg/s), and design pressure ratio for the stage is 2.13. Additional details concerning the SMI rig design are provided in Ref. [9].