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An experimental investigation of a low Reynolds number, high Mach number centrifugal compressor

IP.com Disclosure Number: IPCOM000128049D
Original Publication Date: 1998-Dec-31
Included in the Prior Art Database: 2005-Sep-14
Document File: 6 page(s) / 21K

Publishing Venue

Software Patent Institute

Related People

Shirley, Gregory B: AUTHOR [+3]

Related Documents

http://theses.mit.edu:80/Dienst/UI/2.0/Describe/0018.mit.theses/1998-217: URL

Abstract

Experiments were performed on a super-scale test facility to study the performance of very small centrifugal compressors suitable for microfabrication. The test facility was 75 times larger than the full-scale device and operated under 1/75 atmospheric pressure conditions to correctly match the Reynolds number, which is about 20,000. The impeller tip speed of the test facility matched those in the design full-scale device to capture the effects of compressibility.

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 This record is the front matter from a document that appears on a server at MIT and is used through permission from MIT. See http://theses.mit.edu:80/Dienst/UI/2.0/Describe/0018.mit.theses/1998-217 for copyright details and for the full document in image form.

An Experimental Investigation of a Low Reynolds Number, High Mach Number Centrifugal Compressor

by

Gregory B. Shirley
B.S.E., Mechanical and Aerospace Engineering Princeton University 1996 Submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE in AERONAUTICS AND ASTRONAUTICS

at the Massachusetts Institute of Technology

September 1998
SIGNATURE OF author: [[signature omitted]]

Department of Aeronautic and Astronautics

August 10 1998

CERTIFIED BY: [[SIGNATURE OMITTED]]

Alan H. Epstein R.C. Maclaurin Professor of Aeronautics and Astronautics ACCEPTED BY: [[SIGNATURE OMITTED]]

Jaime Peraire Chairman, Department Graduate Committee ARCHIVES MASSACHUSETTS INSTITUTE OF TECHNOLOGY LIBRARIES SEP 22 1998

Massachusetts Institute of Technology Page 1 Dec 31, 1998

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An experimental investigation of a low Reynolds number, high Mach number centrifugal compressor

An Experimental Investigation of a Low Reynolds Number, High Mach Number Centrifugal Compressor

by

Gregory B. Shirley

Submitted to the Department of Aeronautics and Astronautics On August 10, 1998 in Partial Fulfillment of the Requirements for the Degree of Master of Science in Aeronautics and Astronautics

ABSTRACT

Experiments were performed on a super-scale test facility to study the performance of very small centrifugal compressors suitable for microfabrication. The test facility was 75 times larger than the full-scale device and operated under 1/75 atmospheric pressure conditions to correctly match the Reynolds number, which is about 20,000. The impeller tip speed of the test facility matched those in the design full-scale device to capture the effects of compressibility.

Two compressor geometries were tested, one with and one without diffuser vanes; the same impeller was used in both cases. For each of the diffuser designs, speedlines were determined at impeller tip speeds of 400 m/s, corresponding to 100% of the design value, and 170 m/s, corresponding to 42% of design. Detailed measurements were made at a single operating point on each of the speedlines.

The test results show that the total-to-static pressure ratios developed by the facility are in agreement with CFD prediction. The measured mass flow rates are between the values predicted by 2-D and 3-D CFD. The performance of the vaned diffuser (Cp=0.48) is superior to that of the vaneless diffuser (Cp=0.24) in recovering the dynamic pressure of air exiting the impeller. The impeller isentropic efficiencies are about 0.48 and 0.27 for 100% and 42% design impeller speeds, respectively. These values are substantially lower than the predictions of CFD. The difference is thought to be due in part to the interaction of the flow in the i...