W-1A Facility Description
This unique facility provides for an increased understanding of the complex flow phenomena within the curved centrifugal channels and multi-stage axial compressors. W-1A can be configured with either a 5-ft diameter centrifugal or a 4-ft diameter axial flow compressor. Air enters the facility through a filtered roof vent, is conditioned for temperature and turbulence, and then passes through the research compressor. The axial compressor has a removable casing treatment under rotor one, which allows for various tip treatment studies. The axial compressor has been configured for injection of air through the stator footring, stator blades and endwalls to assess flow control. Airflow exiting the compressor is controlled by a throttle valve, close coupled to the collector, and discharged into the atmospheric (axial) or altitude (centrifugal) exhaust system. The compressor rotor is driven by a 1500-hp variable speed drive motor. The increased size and low speed permits instrumentation to be located directly in the compressor's complex flow paths. The detailed flowfield measurements will assess the emerging CFD codes as well as provide data for the development of flow models required by the CFD codes.

W-1A Special Features
Optical access windows in the compressor casing are used in conjunction with nonintrusive measurements and flow visualization techniques. Data such as pressures, temperatures, and flow angles are measured in both rotating and nonrotating passages using standard instrumentation, hot wires, flow visualization, trace gases, and LDV, PIV and pressure sensitive paint. Data recording, processing, and display are accomplished through the facility's distributed data acquisition system, described later, with input data from analog and discrete inputs or steady-state pressure inputs from the Electronic Scanned Pressure (ESP) system.