An Investigation on Data Processing in Transition Detection Using Surface Pressure Fluctuation
利用表面脉动压力探测转捩的数据处理方法研究

Transition detection based on surface pressure fluctuation is a promising technique of transition detection. Generally, the R.M.S.(Root Mean Square) change of pressure fluctuation and power spectrum are taken as judgement evidence. Aiming at the problems of current signal processing method (only applicable to single point judgement and poor effect of judgement), authors conducted this study. Through theoretical analysis, new methods are put forward:(1) nondimensionalization of the R.M.S. of pressure fluctuations by using combination of local dynamic pressure and R.M.S. of transducer singal in zero state; (2) to select suitable frequency range and express power spectral. The measured data of surface pressure fluctuation on an airfoil was compared with the results obtained by traditional method. Conclusions show that new data processing method has good regularity, is more visual and more suitable for multi-point mesurement in transition detection along flow direction. Above results may be helpful for engineers of wind tunnel.