DERIVATION OF COMPRESSOR STAGE CHARACTERISTICS, FOR ACCURATE OVERALL PERFORMANCE MAP PREDICTION

In the present paper a method for deriving stage characteristics, which can provide accurate prediction of a multistage compressor map is presented. The method combines optimization techniques with the principles of stage stacking. The stage characteristics are produced by modifying some initial generic ones, until the desired accuracy in the prediction at selected points on the overall map is achieved. There are several reasons why prediction based on the initial stage characteristics can be inaccurate, the following three being the main ones. The first is due to inaccuracy in the representation of the stage characteristics themselves. The second is due to lack of exact knowledge of the geometric data of the various stages. Finally the third reason consists of the “weak” modelling representation of complex physical phenomena with one dimensional approaches. Therefore, even when the exact stage characteristics are known, this does not guarantee the accurate prediction of the compressor performance. On account of the above, it is preferable to acquire realistic “effective” stage characteristics which can be used for synthesizing overall compressor characteristics and assessing the effects of stage faults. In this paper, both of these aspects are successfully tackled as demonstrated by applying the method to different test cases.Copyright © 1994 by ASME