Axial Compressor Stall and Surge Prediction by Measurements

Abstract

The paper deals with experimental investigations and analyses of unsteady pressure distributions in different axial compressors. Based on measurements in a single stage research compressor the influence of increasing aerodynamic load onto the pressure and velocity fluctuations is demonstrated. Detailed measurements in a 14-stage and a 17-stage gas turbine compressor are reported. For both compressors parameters could be found which are clearly influenced by the aerodynamic load.For the 14-stage compressor the principles for the monitoring of aerodynamic load and stall are reported. Results derived from a monitoring system for multi stage compressors based on these principles are demonstrated. For the 17-stage compressor the data enhancement of the measuring signals is shown. The parameters derived from these results provide a good base for the development of another prediction method for the compressor stability limit. In order design an on-line system the classification of the operating and load conditions is provided by a neural net. The training results of the net show a good agreement with different experiments.