Accession Number : ADA303235

Title :   Prediction of an Axial Compressor Stage Characteristic from a One-Point Measurement.

Descriptive Note : Master's thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH

Personal Author(s) : Punjani, Shahnaz M.

PDF Url : ADA303235

Report Date : DEC 1995

Pagination or Media Count : 137

Abstract : This study focuses on predicting axial compressor stage characteristics using a single performance point comprised of mass flow, temperature and pressure rise coefficients obtained in experimental testing and a generic stage temperature characteristic. A new temperature characteristic is generated using a mapping technique where changes in stage blade angles are iterated from assumptions of free vortex flow and constant increment of flow turning angle with increased flow incidence. If additional data corresponding to the new curve are available, the characteristic is adjusted using non-linear least squares estimation, Essentially, the modified mapped curve results from a re-estimated change in the stator outlet angle which is iterated to minimize the total error between the new curve and the new aggregate of the given data. A pressure characteristic for the single data point may be predicted from the new temperature characteristic and an assumption of constant efficiency. Upon collection of additional data points, an improved pressure characteristic is obtained using an improved model for efficiency. The predicted characteristics agreed well with calibration data in pre-stall regions. For those data near stall, the assumed linear relationship between incidence and flow turning is invalid, and a new model for flow turning is required. (AN)

Descriptors :   *AXIAL FLOW COMPRESSORS, VELOCITY, PRESSURE GRADIENTS, DATA BASES, MATHEMATICAL MODELS, ALGORITHMS, ACCURACY, EFFICIENCY, THESES, BOUNDARY LAYER, VORTICES, MASS FLOW, STALLING, TEMPERATURE GRADIENTS, MATHEMATICAL PREDICTION, ERROR ANALYSIS, LEAST SQUARES METHOD, NONLINEAR ANALYSIS, MACH NUMBER, INLETS, MAPPING(TRANSFORMATIONS), INCOMPRESSIBLE FLOW, GOODNESS OF FIT TESTS, RADIAL FLOW, CURVE FITTING, CASCADES(FLUID DYNAMICS), AXIAL FLOW COMPRESSOR BLADES, CENTRIFUGAL PUMPS.

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE