2．4犿跨声速风洞连续变迎角试验关键技术研究

摘要

The three key technical problems have be met in developing the continuous sweep-ing angle of attack test technique in 2 .4m transonic wind tunnel.First,it is difficult to compen-sate transonic flow field quickly and accurately because of persistent disturbances.Second,it is difficult to filter and denoise test data because of overlapped frequencies of useful and disturbing signals.Third,it is difficult to synchronize test data because of actual signals being not synchro-nized.In order to solve these problems,a series of research and development were carried out. Quick compensation of flow field is achieved through optimizing PID(Proportional Integral Differ-ential)parameters and optimizing filter of total and static pressure signals.Test signals are de-noised through a combined filtering approach of software,hardware and wavelet.Cross-correla-tion function is used in synchronizing wind tunnel test signals.Based on above research work,the technique of continuous sweeping angle of attack for force measurement test in 2 .4m transonic wind tunnel was achieved.This technique is verified through J7 calibration model,and test re-sults show that the technical problems mentioned above are solved effectively.Mach number con-trol precision has reached ±0.002 and the results have good consistency with those of conven-tional pitch-and-pause testing mode.%在2．4m跨声速风洞开展连续变迎角试验技术研究中，遇到了3个难题：跨声速流场被持续扰动，快速精确补偿困难；试验有用信号频率与干扰信号频率产生重叠，降噪处理困难；信号间不同步对试验数据的影响增大，信号精确同步困难。采用总静压滤波优化和PID（Proportional Integral Differential）调节优化等方法提高流场快速跟随性，硬件＋软件＋小波等复合滤波方式进行降噪处理，并利用互相关函数实现各信号的精确同步，建立了2．4m跨声速风洞连续变迎角试验技术。使用J7等标模对该项技术进行了验证，结果表明，上述问题均得到有效解决，连续变迎角试验流场犕犪数稳定在±0．002范围内，数据的精准度达到阶梯测力试验水平。