Based on characteristics of fluid machinery in two aspects

namely mechanical feature and fluid flow

the strangeness and unstable flow charachteristics have been extracted from mutiple parameter characteristics of the fluid machinery through analysis of mechanical and unstable flow faults for typical fluid machinery in power plants. Based on experimental study on a 4-43 type ventilator

the qualitative and quantitative strangeness characteristics have been deduced by using wavelet analysis. On the basis of frequency varying character of unstable flow

multiple parameter unstable flow characteristics have been analysed and given

providing basis for multiple parameter characteristics for fault diagnosis of the fluid machinery.