Experimental Study Of Online Warning And Self-adaptive Adjustment To Surge In A Centrifugal Fan

At the base of carrying out the objective, which the online warning and self-adaptive adjustment techniques are implemented to flow instabilities (surge and rotating stall) in the centrifugal fan, the surge inception is analyzed by use of methods related to temporal domain, frequency spectra, and wavelet analysis in the thesis. Meantime, the earliest occurring location of surge precursor, frequency characteristic of surge, and the amplitude successive tendency are identified. With the understanding of above-mentioned the investigated results, the methods of the online warning and self-adaptive adjustment are designed. Practically, It means to make use of analytical capacity from Lab VIEW experimental software, for designing the related codes, which are closely referred to the altering tendency of both power spectrum and amplitude of the surge precursor. Then, the signals and results are utilized to control the starting of high response servomotor and actuator, through data-analogy convector, which is connected with computer. Finally, we realize the first objective depending on computer's controlled program.It is the final purpose to execute the online warning and self-adaptive adjustment to surge, for getting rid of computer's restriction. Under the fundamentals of experimental study, we combine the identifying criterion on surge precursor (frequency analysis and amplitude increment) and techniques of automatic control. The DSP (Digital Signal Processor) electric circuit board is utilized to diagnose the warning and self-adaptive adjustment of surge real-timely. The experimental investigation will provide a new exploring way for real-timely controlling flow instabilities from internal flow in turbomachinery.