Characterization of Aerodynamic Forcing Functions for Embedded Rotor Resonant Response in a Multistage Compressor

Nicholas J. Kormanik, Purdue University

Abstract

There are two main objectives associated with this research: The first portion examines the flow field within the embedded stage of the Purdue 3-Stage Axial Compressor and the aerodynamics responsible for exciting a forced response condition on an embedded rotor. The second portion focuses on the upgrades made to the facility to accommodate a new compressor design, as well as the basic performance characteristics that were acquired for the baseline model. With the first phase of this research endeavor, the first chord-wise bending vibratory mode was examined with a standard stator 1 (S1) blade-count configuration (44 vanes). Next, a reduced S1 blade-count configuration (38 vanes) was implemented to observe how a reduced vane count might impact the forced response at the first torsion vibratory mode. To capture these aerodynamic considerations, stagnation pressure and thermal anemometry probes were used throughout the embedded stage to provide a detailed picture of the influence associated with rotor and stator wakes. These data were also used to observe the potential field effects from the downstream blade-rows. The overall purpose of this campaign was to provide accurate and reliable dataset that could be used to further enhance and validate the computational aeromechanics tools used by the GUIde V consortium, the sponsors for this research. The second phase of this involves the redesign of the Purdue 3-Stage Axial Compressor Facility to accommodate a new compressor, designed by Rolls-Royce, that requires higher mass flow rates, pressure ratios, speeds, and temperatures. Along with many of the mechanical upgrades associated with an adaptation of the driveline and throttle system, health-monitoring upgrades were made to improve the safety and integrity of the compressor system, particularly with respect to temperature and vibrations. Instrumentation improvements include new pressure transducers to observe higher pressures and mass flow rates and the implementation of a tip clearance measurement system. Finally, structural improvements include reinforcement of the struts to account for higher thrust and modification of the rear bearing plate to accommodate an increase in bleed flow under the shroud of the rear stator. In addition to these facility upgrades, an inlet pressure study was performed and aeromechanical considerations were observed. All this work culminated in the acquisition of a steady performance map that was produced for the baseline configuration of the new compressor design, which will be compared to for future design iterations.

Degree

M.S.A.A.

Advisors

Key, Purdue University.

Subject Area

Engineering|Aerospace engineering|Mechanical engineering

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