Accession Number:

AD0769415

Title:

An Analytical Analysis of the Effects of Instantaneous Vorticity on Compressor Performance.

Descriptive Note:

Master's thesis,

Corporate Author:

NAVAL POSTGRADUATE SCHOOL MONTEREY CALIF

Personal Author(s):

• Shoemaker,James Edward

Report Date:

1973-06-01

Pagination or Media Count:

89.0

Abstract:

Vorticity forms the basis for a new approach to the analysis of inlet distortion in axial flow fans and compressors. Farmer first formulated this approach and this paper represents a test of the usefulness of his theory. A summary of recent developments in the field along with a discussion of the effects of distortion on stall margin forms a background for this complex problem. A computer program calculates the vorticity pattern at the compressor face using data that are read from a magnetic tape. The data, which were provided by NASA Lewis Research Center in Cleveland, consist of eleven stall events. The output of the program contains tables of stagnation pressure and the partial derivatives of pressure and the partial derivatives of pressure in the R and theta directions as well as three maps. The three maps are of pressure and radial and circumferential vorticity. The results of the program show a correlation between a ring of large positive circumferential vorticity and stall, leading to the conclusion that the stall was caused by the increase in blade loading induced by the vorticity. This conclusion suggests a formulation for a universal inlet distortion index and provides a basis for the evaluation of the vorticity approach to the problem. Author

Descriptors:

• *TURBOFAN ENGINES
• SURGES
• THESES
• VORTICES
• DUCT INLETS
• DISTRIBUTION
• COMPUTER PROGRAMS

Subject Categories:

• Fluid Mechanics
• Jet and Gas Turbine Engines

Distribution Statement:

APPROVED FOR PUBLIC RELEASE