Experimental investigation of an aspirated fan stage

This thesis focuses on the use of aspiration on compressor blade design. The pressure ratio can be significantly increased by controlling the development of the blade and endwall boundary layers. This concept is validated through an aspirated fan stage experiment performed in the MIT Blowdown Compressor Facility. The fan stage was designed to produce a pressure ratio of 1.6 at a throughflow adiabatic efficiency of 89% at a rotor tip speed of 750 ft/s. Aspiration equal to 0.5% of the inlet flow was applied to the blade surface of both the rotor and stator. Aspiration was also used on the endwall boundary layers. Detailed flowfield measurements are made behind the rotor and stator, and the ensemble-averaged data is compared with a 3-D, viscous analysis tool. The time-accurate flow measurements show a large blade to blade variation due to unsteady vortex shedding, which is not captured by conventional 3-D, viscous analysis tools. An incompressible, vortex shedding model calibrated to the experimental data shows that the vortex shedding induces radial flows that redistribute flow properties in the spanwise direction. 'Correction' of the experimental data using the model gives a better comparison with the 3-D, viscous analysis solution. In order to understand the possible benefits of aspiration, a meanline parameter study is performed over a range of rotor inlet Mach numbers, flow coefficients, and work coefficients. Viscous and shock losses are estimated for both conventional and aspirated stages. The results suggest that aspiration can have the largest impact on compressor performance at high stage pressure ratios.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Aeronautics and Astronautics.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2001

Author dc:creator

• Schuler, Brian Joseph, 1974-

Advisor dc:contributor.advisor

• Jack L. Kerrebrock.

• Aeronautics and Astronautics.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/8108

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/8108